Introduction

The phylogenetic arrangement of the Pleurothallidinae subtribe initially included nine affinities: Acianthera Scheidw., Dilomilis Raf., Lepanthes Sw., Masdevallia Ruiz & Pav., Octomeria R.Br., Phloeophila Hoehne & Schltr., Pleurothallis R.Br., Restrepia Kunth, and Specklinia Lindl. (Karremans 2016). But the Dilomilis affinity was subsequently separated and recognized as its own subtribe, Dilomilinae (Dietrich in Dietrich et al. 2007, Karremans & Vieira-Uribe 2020). Following Karremans (2016), Bogarín, Karremans & Fernández (2018) and Bogarín et al. (2019), the Lepanthes affinity now encompasses 14 genera: Anathallis Barb.Rodr., Draconanthes (Luer) Luer, Frondaria Luer, Gravendeelia Bogarín & Karremans, Lankesteriana Karremans, Lepanthes Sw., Lepanthopsis (Cogn.) Ames, Opilionanthe Karremans & Bogarín, Pendusalpinx Karremans & Mel.Fernández, Pseudolepanthes (Luer) Archila, Stellamaris Mel.Fernández & Bogarín, Trichosalpinx Luer, Tubella (Luer) Archila, and Zootrophion Luer. It is worth noting that the name Tubella was found to be an invalid in Orchidaceae and has been replaced with Karma Karremans (2023). Six genera of the Lepanthes affinity are presented in Mexico: Anathallis, Lankesteriana, Karma, Lepanthes, Lepanthopsis, and Trichosalpinx. With the exception of Lepanthes, which boast nearly 70 species in Mexico, the other four genera within this affinity are each represented by seven or fewer species in this country.

Anathallis was originally proposed to accommodate two Brazilian species, A. fasciculata Barb. Rodr. and A. racemosa Barb.Rodr. Over time, the former name has been considered a synonym of A. obovata (Lindl.) Pridgeon & M.W.Chase and was designated as the lectotype of the genus (Garay 1974). On the other hand, A. racemosa is currently treated as a synonym of Stelis aurea (Lindl.) Karremans. For a long time Anathallis remained subsumed within the synonymy of Pleurothallis (Cogniaux 1896, Garay 1974, Luer 1986). However, Pridgeon, Solano & Chase (2001) demonstrated that Pleurothallis, as delimited by Luer (1986), was polyphyletic, and various unrelated groups were segregated into distinct genera (Pridgeon & Chase 2001, 2002). Consequently, Anathallis was redefined to encompasses Pleurothallis sect. Acuminatae Lindl. and P. sect. Muscosae Lindl. (Pridgeon & Chase 2001, Pridgeon, 2005). Subsequent studies revealed that Anathallis barbulata (Lindl.) Pridgeon & M.W.Chase and similar species formed a clade closely related to Trichosalpinx, prompting their segregation into Lankesteriana. Meanwhile, Pleurothallis sect. Acuminatae was found to be closely related to Stelis Sw. and their species were accordingly transferred (Karremans 2014).

On the other hand, Luer (2006) proposed Panmorphia Luer to include Pleurothallis sect. Muscosae and Palmoglossum Klotzsch ex Rchb.f., with P. sertularioides (Sw.) Spreng. designed as the type species. However, Panmorphia also encompasses Pleurothallis barbulata and related species currently classified under Lankesteriana. Additionally, P. sertularioides, the type species of Panmorphia, has been found to be nested within Anathallis and closely related to A. obovata, the type species of Anathallis (Chiron, Guiard & van den Berg 2012, Karremans 2014, Bogarin et al. 2018). Consequently, Panmorphia is nonmonophyletic and cannot be distinguished from Anathallis. Nevertheless, Archila (2014(2015)a) transferred 54 binomials from Anathallis, Panmorphia (including Lankesteriana), and Specklinia to Trichosalpinx, rendering this genus paraphyletic. Anathallis is recognized here as a monophyletic group based on Pleurothallis sect. Alatae Luer and Panmorphia (excluding species of Lankesteriana), as delimitated by Karremans (2014), Bogarín et al. (2018), and Karremans & Vieira-Uribe (2020).

Anathallis extends its northern distribution to Mexico, where its richness is comparatively lower than in South America. At the start of the 21st century, eight Mexican Pleurothallis species were reclassified into the genus Anathallis by Pridgeon & Chase (2001, 2002). These species included A. abbreviata (Schltr.) Pridgeon & M.W.Chase, A. barbulata, A. comayaguensis (Ames) Pridgeon & M.W.Chase, A. dolichopus (Schltr.) Pridgeon & M.W.Chase, A. minutalis (Lindl.) Pridgeon & M.W.Chase, A. platystylis (Schltr.) Pridgeon & M.W.Chase, A. scariosa (Lex.) Pridgeon & M.W.Chase, and A. sertularioides (Sw.) Pridgeon & M.W.Chase. Later, additional combinations were made in Anathallis for Pleurothallis haberi Luer, P. involuta L.O.Williams, P. lewisiae Ames, P. oblanceolata L.O.Williams, and P. yucatanensis Ames & C.Schweinf., and a new species, A. greenwoodii Soto Arenas & Salazar, was described (Hágsater & Soto-Arenas 2003). As a result, Soto-Arenas et al. (2007) included 14 Mexican species in Anathallis. However, within this genus, there was a grouping of small plants with rhizomatous habit and successively flowered racemes (e.g., A. barbulata and A. minutalis and their allies), alongside larger plants with caespitous habit and simultaneously flowered raceme (e.g., A. dolichopus, A. platystylis, and A. scariosa). Karremans (2014) further separated the species with a minute habit, frequently congested raceme, fused lateral sepals, and tailed apices of sepals and petals in Lankesteriana, which encompasses five Mexican species (A. abbreviata, A. barbulata, A. comayaguensis, A. involuta, and A. haberi). Anathallis platystylis, A. dolichopus, and A. scariosa shared morphological characteristics with Stelis (e.g., large plant size, caespitous habit, racemes longer than the leaves, simultaneously flowering, and partially fussed lateral sepals), and were consequently reclassified accordingly (Solano 2008c; Karremans 2014). Currently, Anathallis comprises six species in Mexico: A. greenwoodii, A. lewisiae, A. minutalis, A. oblanceolata (L.O.Williams) Solano & Soto-Arenas, A. sertularioides, and A. yucatanensis (Ames & C. Schweinf.) Solano & Soto-Arenas. But the current name of one of them, A greenwoodii, needs to be transferred to another genus within the Lepanthes affinity. The objective of this study was elaborate the taxonomic treatment of this group by reviewing live specimens, material in scientific collections, and specialized literature.

Material and methods

Information sources.-- Nomenclatural information was obtained from type specimens and original descriptions. For publications, the protologues were accessed through the Biodiversity Heritage Library (http://www.biodiversitylibrary.org). Type specimens were revised from the AMO herbarium and online collections at the Field Museum of Natural History (F, http://fieldmuseum.org/explore/department/botany/collections), Missouri Botanical Garden (MO, http://www.mobot.org), Naturhistorisches Museum Wien (W, http://www.nhm-wien.ac.at/en/research/botany), Oak Ames Orchid Herbarium (AMES, vard.edu), Smithsonian Institution (US, botany.si.edu/), and Swedish Museum of Natural History (S, http://www.nrm.se/). Mexican specimens of Anathallis were thoroughly examined by directly consulting of AMO, ARIZ, ASU, ENCB, FCME, FEZA, HEM, IEB, MEXU, OAX, UAMIZ, TEX, XAL, and XALU herbaria. Other specimens were accessed through online searches of the herbaria AMES, BM, F, K, MO, P, US, and W, as well as from the Global Biodiversity Information Facility (https://www.gbif.org), SEINet data portal (https//:swbiodiversity.org/seinet/index.php), and the citizen science network iNaturalista (http://www.naturalista.mx). The taxonomic identity of all specimens was verified.

Line drawings were prepared for each species using fresh or rehydrated specimens. Adrawing tube adapted to a stereomicroscope (Wild Heerbrugg Type 308700, Gais, Switzerland) was used for this purpose. For each species, comprehensive information is provided, including nomenclature, distribution, habitat, phenology, comparison with similar taxa, conservation status as per Mexican regulations (SEMARNAT 2010), taxonomic notes, and specimens with documented presence in Mexico. Mexican states, floristic provinces (Rzedowski & Reyna-Trujillo 1990), and countries where each species has been recorded were assigned. The vegetation type where each species has been reported follows Rzedowski (2006). Keys for genera within the Lepanthes affinity found in Mexico and Mexican species of Anathallis were also prepared. Some clarifications regarding the usage of terms employed here in the morphology of plants of the Pleurothallidinae subtribe are provided below. The term ‘sympodium’ follows Dressler (1993) and Pridgeon et al. (2005); for ‘bilabiate flower,’ Fon-Quer (2000) is followed. Regarding the use of ‘stem’ instead of ‘ramicaule’ to denote the caulinar axis bearing leaves and inflorescences in a Pleurothallidinae, Rasmussen (1985) and Solano (2015) were adopted.

Potential distribution modeling.-- The geographic coordinates of each species’ locality records were determined whenever available information allowed. Subsequently, they were overlaid onto a digital elevation model map of Mexico using QGIS 3.22.9 (QGIS Development Team 2023). A vector layer was created to serve as a reference region for each species’ distribution, referred as area M, which was generated by summing the areas occupied by the species’ localities on layers for political divisions (INEGI 2021), floristic provinces (Rzedowski & Reyna-Trujillo 1990), and vegetation types of Mexico (INEGI 2017). The layers with 19 bioclimatic variables were obtained from WorldClim (https://www.worldclim.org/data/bioclim.html) at a resolution of 30 s.

Additionally, the digital elevation model of Mexico was obtained and cropped to match the size of area M for each species. Since these layers could exhibit high correlation, we initially ran a model in MaxEnt 3.4.1 (Phillipps et al. 2023) to select a subset of the least correlated variables. We then used this subset to create the final model, utilizing between 5 and 11 variables per model.

In MaxEnt, default options were used, with Hinge features deactivated, and Create response curves and Do jackknife to measure variable importance activated, using a logistic model as the output format. In Settings/basic, the Random seed function was activated, and a value of 30% was assigned to the Random test percentage function, selecting 100 replicates per model and one run per Bootstrap. In the Settings/advanced section, the Write plot data function was activated, while Extrapolate and Do clamping were deactivated. The Apply threshold rule was set at the 10-percentile training presence. Subsequently, the command was executed, and the model was run.

To select the best model for each species, we considered the area under the curve (AUC) with the following criteria: 0.9-1.0 (excellent), 0.8-0.9 (good), 0.7-0.8 (acceptable), 0.6-0.7 (poor), and 0.5-0.6 (failed). Model selection also considered models that utilized the largest subset of environmental variables while minimizing the omission of known localities. Values greater than 0.8 were achieved when modeling included at least 12 localities for each species. The habitat suitability level for the model was categorized into four classes: not suitable (≤0.10), low suitability (0.11-0.30), moderate suitability (0.31-0.70), and high suitability (≥0.71) (Deb, Jamir & Kikon 2017, Usmadi et al. 2023).

Conservation status assessment.-- The conservation status of each species was assigned using the Species Risk Assessment Method (MER by its acronym in Spanish) for wild species in Mexico, as described in Annex Normative II of NOM059-SEMARNAT-2010 (SEMARNAT 2010). This method standardizes the decision criteria for risk categories using taxon-specific information. It is based on four independent criteria: A) the extent of the taxon’s distribution in Mexico, B) the status of the habitat concerning the taxon’s natural development, C) the intrinsic biological vulnerability of the taxon, and D) the impact of human activity on the taxon. Each of these criteria has several subcriteria that are numerically evaluated in ascending order of risk. For each criterion, the sum of the points is normalized against its maximum score, so the maximum value is 1. The sum of the values assigned to the four criteria represents the cumulative risk assessment.

Key for the genera of Lepanthes affinity in Mexico

Mexican species of Lepanthes affinity belong to the following six genera, they can be identified with the following key.

Taxonomic Treatment

AnathallisBarb.Rodr., Gen. Sp. Orch. 1: 23. 1877.

Lectotype (designated by Garay, 1974): Anathallis fasciculata Barb.Rodr., Gen. Sp. Orch. 1: 23. 1877 = Anathallis obovata (Lindl.) Pridgeon & M.W.Chase.

Syn.: Palmoglossum Klotzsch ex Rchb.f. Xenia Orchid. 1: 174. 1856, nom. illeg., based on Pleurothallis crassifolia Rchb.f. nom. illeg., not Focke (1849).

Syn.: Pleurothallis sect. Anathallis (Barb.Rodr.) Cogn. Fl. Bras. 3(4): 380. 1896.

Syn.: Pleurothallis sect. Margaritifera Schltr. Notizbl. Bot. Gart. Berlin-Dahlem 7: 272. 1918, nom. illeg., based on Plurothallis margaritifera Schltr.

Syn.: Pleurothallis sect. Alatae Luer, Monogr. Syst. Bot. Missouri Bot. Gard. 76: 99. 1999. Type: Pleurothallis obovata Lindl. = Anathallis obovata.

Syn.: PanmorphiaLuer, Monogr. Syst. Bot. Missouri Bot. Gard. 105: 144. 2006. Type: Epidendrum sertularioides Sw. = Anathallis sertularioides.

Minute epiphytes or lithophytes plants. Rhizome relatively elongated, erect, or creeping, formed by 3 internodes between adjacent stems. Roots flexuous, whitish, terete. Stem terete, abbreviated, formed by two internodes, with an annulus near the apex of the upper internode, covered by tubular, obtuse, mucronate, scarious, and overlapping sheaths. Leaf fleshy or fleshy thickened, emarginate and mucronate at the apex, petiolate to subpeciolate. Inflorescence emerging from the annulus, equal to or longer than the leaf, racemose; covered at the base by a conduplicate, scarious, and carinate spathaceous bract; peduncle filiform, with 1-3 membranaceous, tubular bracts. Floral bracts obliquely infundibuliform, obtuse, minutely mucronate, membranaceous. Flowers tiny, half open, successive, or simultaneous. Sepals free, acuminate, or acute at the apex, translucent, glabrous, somewhat fleshy. Petals porrect, acuminate or acute at the apex, translucent, glabrous, sometimes ciliated. Lip vibratile, unguiculate, entire or shortly 3-lobed, attached to the foot column by an oblong, membranous claw. Column arcuate or erect, channeled ventrally, wings prominent and a conspicuous foot, clinandrium covering the anther. Stigma a ventral cavity, viscous; rostellum laminar, helmet-like. Anther ventral; pollinia two, yellow, laterally compressed, provided with laminar caudicles, curved and divergent from each other. Ovary trigonous, arching, glabrous, articulated to a terete pedicel. Capsule ellipsoid or obovoid, trigonous, with persistent perianth.

The genus Anathallis comprises just over 120 species distributed in the Neotropics, from Mexico, extending southward to Bolivia and southern Brazil, including the Antilles (Pridgeon 2005). In Mexico, species of this genus are distributed from Jalisco, Guanajuato, and northern Puebla and Veracruz to Chiapas and the southern Yucatan Peninsula (Fig. 1).

The five species of Anathallis can be identified with the following key:

Anathallis lewisiae (Ames) Solano & Soto Arenas, Icon. Orchid. 5-6: x. 2003.

≡ Pleurothallis lewisiae Ames, Proc. Bol. Soc. Washington 44: 42. 1931.

≡ Specklinia lewisiae (Ames) Luer, Monogr. Syst. Bot. Missouri Bot. Gard. 95: 261. 2004.

≡ Panmorphia lewisiae (Ames) Luer, Monogr. Syst. Bot. Missouri Bot. Gard. 105: 164-165, f. 129. 2006.

≡ Trichosalpinx lewisiae (Ames) Archila, Revista Guatemalensis 17: 70. 2014(2015).

TYPE: GUATEMALA. Department of Izabal, near Puerto Barrios, on a mango tree about forty miles from the coast, 175 feet, August 1930, M.W. Lewis 2 (holotype: AMES-74405!; isotype: AMES-74406!).

Rhizomatous, scandent, epiphyte herb, up to 2 cm tall. Roots 0.5-0.7 mm diameter. Rhizome 3.0-6.5 mm long between adjacent stems, 0.8 mm diameter. Stem 1-4 mm long, the annulus 0.6-1.5 mm below the apex. Leaf 6-15 × 4.5-8.0 mm, fleshy, slightly arcuate, elliptic, orbicular-elliptic or obovate, rounded, subpetiolate, adaxially rough-warty. Inflorescence 1-2 per stem, as long as the leaf, 5-15 mm long; peduncle 3-9 mm long, 0.25 mm diameter, the base covered by a spathaceous bract 0.5 mm long, with 1 additional tubular bract, 0.5 mm long; rachis with 2-4 successive flowers. Floral bracts hispidulous, 1.0-1.7 mm long. Flowers 4.3-4.5 mm tall, 6.4 mm long, 3.7 mm wide, sepals and petals yellowish to green-yellowish, purple at their apices, lip purple, column yellow-greenish and purple at the apex. Sepals conduplicate, 3-veined; dorsal sepal oblong-lanceolate, acute, 4.4-5.0 × 1.8-2.0 mm; lateral sepals 4.3-5 × 1.3-1.5 mm, obliquely lanceolate, acute. Petals oblong, obtuse to rounded, shortly apiculate, glandular-papillose, 1-nerved, 3.5-3.7 × 0.9-1.2 mm. Lip 2.3-3.0 × 0.6-1 mm, minutely 3-lobed, oblong, acute, 3-nerved, glandular-papillose; lateral lobes near the middle, triangular-rounded, erect; the blade with a pair of submarginal calli along the middle part, channeled among them, with a pair of mammillae calli at the base. Column 1.8-2.6 mm long, 0.9 mm wide, slightly arcuate, wigs oblong, erose along the margins, clinandrium lacerate, foot column 1 mm long. Anther subglobose, 0.45 mm long and wide. Pollinia 0.45 mm long, obovoid. Ovary 0.9-1.5 mm long, pedicel 1.5-2.5 mm long. Capsule not seen. (Fig. 2-3).

Distribution: Mexico, Guatemala, Belize, Honduras, Nicaragua, Costa Rica, and Panama. In Mexico it is found in the Gulf of Mexico Coast floristic province, in Chiapas, Oaxaca, and Veracruz states. The accepted distribution model for A. lewisiae yield a predicted AUC = 0.861, where the most influential variables being precipitation in the wettest month (41.8%), annual temperature range (32.1%), and the Mexican digital elevation model (11.3%). The model predicted three primary areas with the highest probability of distribution: the Lacandon forest (Chiapas), Los Chimalapas-Uxpanapa (Oaxaca, Veracruz), and Los Tuxtlas (Veracruz). For A. lewisiae, the potential distribution area was estimated to be 27,649.9 km², equivalent to 1.41% of Mexico’s total territory (Fig. 4).

Habitat: Epiphyte in evergreen tropical forest, semideciduous tropical forest, and mangrove swamp at elevations ranging 3 to 400 m.

Phenology: It flowers from May to December.

Taxonomic notes: This species is characterized by its diminutive, creeping habit, rough-warty leaves, obliquely oblong, obtuse petals with denticulate-cilia, and a shortly 3-lobed, oblong, acute lip (Fig. 2-3). Another species that shares similar characteristics, at least in its floral morphology, is A. sertularioides (Sw.) Pridgeon & M.W.Chase, with which it become sympatric. However, it can be distinguished by its larger and erect habit (vs. scandent), oblanceolate leaves (vs. elliptic, orbicular, or obovate), and single flowered inflorescence (vs. 2-4-flowered inflorescence). Another species with similar habit is A. minutalis (Lindl.) Pridgeon & M.W.Chase, but it can be differentiated by its very fleshy-thickened, obovate to rounded, glabrous leaves (vs. fleshy-thickened, almost orbicular), and entire lip (vs. shortly 3-lobed).

This species was originally described as Pleurothallis lewisiae based on a specimen collected in Izabal, Guatemala (Fig. 5). In Mexico, it was first documented as Pleurothallis lewisiae by Soto-Arenas (1988) from a specimen collected in Chiapas. Subsequently, the taxon has been reported with the same name by Soto-Arenas (1988), Hágsater et al. (1998), Martínez, Ramos & Chiang (1994), and Espejo-Serna & López-Ferrari (1998); as Parmorphia lewisiae by Luer (2023), and as Anathallis lewisiae by Salazar (2013), Villaseñor (2016), and Krömer et al. (2020).

Conservation status. In the four criteria of the MER evaluation, the species obtained the following scores: A) geographic distribution = 0.4545, B) habitat characteristics = 0.2222, C) intrinsic biological vulnerability = 0.1739, and D) impact of human activity = 0.4000; resulting in a total score of 1.2506. Since this value is ≥1.0 and <1.5, and the sum of criterion D is ≥ 0.3, the corresponding risk category is Subject to Special Protection (Pr). In Veracruz, its habitat has undergone significant transformation due livestock, sugarcane plantations, and human settlements. In Oaxaca and Chiapas, however, there are still well-preserved habitat where local populations thrive. Some of these localities are situated within natural protected areas, such as the Los Tuxtlas (Veracruz), Montes Azules (Chiapas), and Lacan-Tun Biosphere Reserves (Chiapas), as well as the Palenque Natural Monument (Chiapas).

Specimens examined. MEXICO. Chiapas: municipio Ocosingo, Chancalá road, Jul 1977, W. R. Thurston 1536 (AMO(photo)!); a 4 km de Crucero Corozal camino Palenque-Boca Lacantum, 10 Aug. 1984, E. Martínez 6883 (MEXU!, MO!), E. Martínez 6935 (MEXU!), E. Martínez 6983 (MEXU!); campamento COFOLASA, 24 Km al SE de Crucero Corozal sobre camino Palenque-Boca Lacantum, 16 Oct. 1984, E. Martínez 8553 (MEXU!), 7 Dec. 1984, E. Martínez 9267 (MEXU!), Boca Lacantum, sobre Carretera Fronteriza del Sur, 26 Oct. 1984, E. Martínez 8741-bis & C. Aguilar (MEXU!); 24 Km al SE de Crucero Corozal sobre camino Palenque-Boca Lacantum, E. Martínez 25454 (MEXU!), E. Martínez 24993 (AMO!); Crucero Corozal, E. Martínez 25454 (CHAPA! MEXU!), E. Martínez 25543-A (AMO!); Crucero Corozal, Aug. 1992, R. Solano 717 (AMO!), R. Solano 835 (AMO!); Estación Biológica Chajul, vereda de Puente Hamaca a la Sabana, G. Salazar 8606 et al. (MEXU!). Estación Biológica Chajul, 26 Jun. 1999, S. Sinaca 2726 (MEXU!); km 60 del camino Chancalá-Monte Líbano, cerca de El Tumbo, entre Metzabok y la Laguna Ocotalito, 18 Jun. 1986, M. Soto 4227-bis & E. Martínez (AMO!); ojo de agua de San Javier, 23 km al SE de Nuevo Guerrero camino a Boca Lacantum, 29 Jan. 1986, E. Martínez 16932 (XAL(mixed with A. sertularioides)!). Oaxaca: municipio San Juan Bautista Tuxtepec, Bethania, 2 Sep. 2020, C. Refugio-Venegas s.n. (OAX!). Municipio Santa María Chimalapa, camino a Santa María Chimalapa, 20 Nov. 2005, M. Martínez-García 132 (MEXU!). Veracruz: municipio Catemaco, Punta Ostión, bahía Sontecomapan, 17 Aug. 1972, J.H. Beaman 6474 (MEXU!). Municipio Las Choapas, A. Franco 103 (XAL). Municipio Hidalgotitlán, P.E. Valdivia 131 (XAL). Municipio San Andrés Tuxtla, cerro Viguía, Estación de Biología Tropical Los Tuxtlas, 16 Nov. 1984, G. Ibarra 2152-bis et al. (MEXU!); Estación de Biología Tropical Los Tuxtlas, G. Salazar s.n. (AMO(drawing)!); Estación de Biología Tropical Los Tuxtlas, límite N sobre camino a Laguna Escondida, 8 Dec. 1984, G. Salazar 225 (AMO! MEXU!); Estación de Biología Tropical Los Tuxtlas, 15 May 1986, S. Sinaca 725 & Chigo (MEXU!).

Naturalista observation: MEXICO. Chiapas: municipio Marqués de Comillas, 11 Jul. 2020, R. Ortiz s.n. (https://www.naturalista.mx/observations/53280908).

Anathallis minutalis (Lindl.) Pridgeon & M.W.Chase, Lindleyana 16(4): 249. 2001.

≡ Pleurothallis crassifolia Rchb.f., Linnaea 22: 832. 1849(1850), nom. illeg., nonFocke, 1849.

≡ Palmoglossum crassifolium Klotzsch ex Reichb.f., Xenia Orchid. 1: 174. 1856, nom. inval.

≡ Pleurothallis minutalisLindl., Folia Orchid. Pleurothallis (9): 40. 1859, replacement name for P. crassifolia Rchb.f.

≡ Humboldtia minutalis (Lindl.) Kuntze, Revis. Gen. Pl. 2: 668. 1891.

≡ Specklinia minutalis (Lindl.) Luer, Monogr. Syst. Bot. Missouri Bot. Gard. 95: 262. 2004.

≡ Panmorphia minutalis (Lindl.) Luer Monogr. Syst. Bot. Missouri Bot. Gard. 105: 167-168, f. 134. 2006.

≡ Trichosalpinx minutalis (Lindl.) Archila, Revista Guatemalensis 17(1): 71. 2014(2015).

TYPE: MEXICO. unknown locality, “blühte im Juli 1839, eine von C. Ehrenberg aus Mexico mitgebrachte Pflanze” (lectotype designated here W-25566! labelled as Palmoglossum crassifolium).

Syn.: Pleurothallis sarcophilla A.Rich. & Galeotti, nomen based on Sierra d’Oajaca à 7000, Juquila, H.G. Galeotti 48 (W-12719! with a watercolor by Galeotti and a floral sketch by Richard).

Syn. Humboldtia pachyphylla Kuntze, Revis. Gen. Pl. 2: 668. 1891, nom. inval., replacement name for Pleurothallis crassifolia Rchb.f.

Rhizomatous, scandent herb, up to 5 cm tall. Roots 0.6-1.0 mm diameter. Rhizome 2-7 mm long between adjacent stems, 0.8-1.0 mm diameter. Stems 2.5-6.0 mm long, 0.5-1.0 mm diameter, arcuate, the annulus 1.5-2.0 mm below the apex. Leaf 18-25 × 4-7 mm, very fleshy-thickened, arcuate, elliptic to obovate, rounded, subpetiolate, the lamina biconvex and axially sulcate. Inflorescence 15-24 mm long, as long as the leaf; peduncle 6-13 mm long, 0.3-0.5 mm diameter, the base covered by a spathaceous bract, 0.4-0.8 mm long, with 1-2 additional tubular bracts, 1-2 mm long; rachis 5-8 mm long, with 2-3 successive flowers. Floral bracts 1-2 mm long, shortly apiculate. Flowers 3.7-5.0 mm tall, 2-3 mm wide, sepals and petals yellowish, sometimes brownish purple tinged toward their apices and along the mid-vein, lip purple, column yellowish, anther purple. Sepals concave, 3-veined; dorsal sepal 4.5-5.0 × 1.5-1.8 mm, ovate, acute; lateral sepals 4.0-4.8 × 1.4-1.5 mm, ovate-lanceolate, oblique, acute, shortly apiculate. Petals 3.0-3.8 × 0.7-0.9 mm, falcate-lanceolate, long acuminate, marginally denticulate, 1-veined. Lip 2.7-3.1 × 0.7-1.0 mm, entire, oblong-pandurate, acute, longitudinally sulcate, glandular-postulate, 3-veined, with a pair of minute protuberances at the base and two sub-marginal, low calli along the basal 2/3; the base with an oblong claw, 0.3 mm. Column 1.7-2.4 mm long, 0.6-0.9 mm wide, arcuate, wings oblong, entire along their margins, with the apex narrowly triangular, acute and incurved, clinandrium denticulate, foot column 0.6-0.7 mm long. Anther orbicular, 0.5-0.8 mm long and wide. Pollinia 0.3 mm long, obovoid, longitudinally cleft. Ovary 0.8-1.5 mm long, pedicel 1.5-6.5 mm long. Capsule 7.5 mm long, 4.2 mm diameter (Fig. 6-7).

Distribution: Mexico and probably Guatemala. It grows at Meridional and Trans-isthmic Highlands floristic provinces, in Colima, Chiapas, Guanajuato, Guerrero, Jalisco, Michoacán, Oaxaca, and Veracruz. The accepted distribution model for A. minutalis yield a predicted AUC = 0.947, with the most influential variables being minimum temperature of the coldest month (28.4%), temperature seasonality (28.2%), and precipitation of the coldest month (13.6). The model identified four primary areas with the highest probability of distribution: Transverse Volcanic System (México, Michoacan, Morelos), Sierra Madre del Sur (Guerrero, Oaxaca), Sierra Madre Oriental (Puebla, Veracruz), and Chiapas Highlands. For A. minutalis the potential distribution area was estimated to be 135,649.95 km², equivalent to 6.90% of Mexico’s total territory (Fig. 8).

Habitat: Epiphyte or lithophyte, in oak forest and semi-deciduous tropical forest, at elevations ranging 1620 to 2450 m. The creeping plants often form carpets on tree’s limbs or rocks covered by mosses or lichens.

Phenology: It flowers from July to November.

Taxonomic notes: Anathallis minutalis is distinguishable by its minute rhizomatous, branching plants, with inconspicuous stems, fleshy-thickened, orbicular-elliptic and subsessile leaves, and 2-flowered raceme shorter than or as long as the leaf (Fig. 6-7). The most similar species is A. oblanceolata, both can be sympatric in some regions in Southern Mexico. However, the later differs by its erect habit (vs. creeping), oblanceolate, long petiolate, and fleshy leaves (vs. orbicular-elliptic, subsessile, fleshy-thickened), lanceolate, acute dorsal sepal (vs. ovate, acute) and the lanceolate lateral sepals (vs. ovate-lanceolate), and lanceolate-ligulate, rounded lip (vs. oblong-pandurate, acute). Another somewhat similar species is A. sertularioides, but it differs by its linear, long petiolate leaves (vs. elliptic, rounded, subsessile) and a single-flowered inflorescence (vs. 2-flowered inflorescence).

Anathallis minutalis was originally described by Reichenbach (1850) as Pleurothallis crassifolia, based on a Mexican specimen from an unknown locality collected in 1839. However, this binomial was deemed an illegitimate homonym due to the previous existence of a similar name by Focke (1849). Subsequently, Lindley (1859) proposed Pleurothallis minutalis as a replacement name. Nearly simultaneously in 1840, a second specimen was collected in Southern Oaxaca, H.G. Galeotti 48 (in W-12719, Fig. 9) and labeled as Pleurothallis sarcophylla, an unpublished name. The sheet includes a watercolor done by Galeotti himself, as well as a floral analysis by A. Richard. Both illustrations depict a plant that coincides with our concept of Anathallis minutalis.

In the protologue of P. crassifolia, Reichenbach (1850) mentioned that Carl A. Ehrenberg obtained the specimen in Mexico, from which the author prepared the description. However, there is no further information about the specimen or the collection where it was deposited. Tropicos indicates the Ehrenberg’s specimen is the holotype of P. crassifolia and that it is deposited in K, but it has not been located. So, according with articles 9.1 and 9.3 of the Shenzhen Code (Turland et al. 2018), a lectotype for P. minutalis is required. Therefore, the Ehrenberg’s specimen in W, labelled as Palmoglossum crassifolium by Reichenbach, was selected here as the lectotype.

Luer (2006) indicated that a specimen collected by Kienast (not Kienert, as the author erroneously wrote), labeled with this name in W (Fig. 15B), is the holotype of Pleurothallis crassifolia. However, Kienast’s specimen was collected in 1878, almost 40 years after Ehrenberg’s specimen, the type for P. crassifolia mentioned by Reichenbach, and nearly 30 years after this author published that name. Therefore, Kienast’s specimen cannot be the type for Reichenbach’s name. The examination of the illustration and plant fragments mounted on Kienast’s sheet indicates that it corresponds to A. oblanceolata. On the other hand, Otto Kuntze (1891) proposed Humboldtia pachyphylla as a replacement name for P. crassifolia. However, since the latter turns out to be an invalid name, Kuntze’s name is also invalid.

Luer (2023) included the name of Epidendrum pygmaeum Hook., originally published by Hooker in 1834, as a synonym of Panmorphia minutalis. However, Hooker’s description and illustration were based on a Brazilian specimen that corresponds to what is now known as Prosthechea pygmaea (Hook.) W.E.Higgins. Furthermore, Hooker himself had described the same Brazilian specimen as Epidendrum pygmaeum a year early (Hooker 1833), making Hooker’s 1833 name a later homonym.

Anathallis minutalis was reported from Puebla by Miguel-Vázquez et al. (2020), but the voucher specimen (Espejo et al. 5366 in UAMIZ) was determined as A. oblanceolata. The species has also been reported in Guatemala by Dix & Dix (2000) and Archila et al. (2018), but no information about voucher specimens is provided. There is a specimen at AMES (M.W. Lewis 26a) obtained from a market of Guatemala City in 1942 and determined by D. S. Correll as Pleurothallis minutalis, which was the basis for its report in Guatemala (Ames & Correll 1952). However, even though the Lewis’ specimen lacks flowers, their oblanceolate leaves with a distinct petiole and inflorescences shorter than the stem show that it is more similar with A. sertularioides. Luer reported the species for Guatemala, too, based on the specimen collected in “Alta Verapaz, Cobán National Park La Choa (the correct name is probably Lachúa), 200 m, 21 Nov. 1990, collected by H. Ibañez sub. C. A. Luer 14861 (MO)”. However, this specimen could be another species, considering that all known records for A. minutalis are from 1620 to 2450 m elevation in Mexico. This Guatemalan locality (at 200 m) is situated in a region of lowlands that is warm and humid, where species of the genus that occur are A. lewisiae, A. sertularioides, and A. yucatanensis.

Hemsley (1882-1886) included P. minutalis in a checklist of Mexican and Central American orchids. By the end of the 19th century, it remained the sole taxon of what now is Anathallis in Mexico. The species has been reported for Mexico as Pleurothallis minutalis by Williams (1951), McVaugh (1985), Soto Arenas (1988), Espejo-Serna & López-Ferrari (1998); as A. minutalis by Nava-Bernal (2007), Solano (2008a), Szeszko-Fabila (2011), Salazar (2013), Solano et al. (2016), Villaseñor (2016), and Krömer et al. (2020); and as Panmorphia minutalis by Luer (2023). A taxonomic treatment for this species was published by García et al. (2003) and Solano (2008a). Unfortunately, the taxon was misinterpretated in these treatments, as they included a specimen of A. oblanceolata illustrated in García et al. (2003).

Conservation status: In the four criteria of the MER evaluation, the species obtained the following scores: A) geographic distribution = 0.3636, B) habitat characteristics = 0.3333, C) intrinsic biological vulnerability = 0.1739, and D) impact of human activity = 0.4000; resulting in a total score of 1.2708. Since this value is ≥1.0 and <1.5, and the sum of criterion D is ≥ 0.3, the corresponding risk category is Subject to Special Protection (Pr). Populations of A. minutalis exhibit generally low densities, but it is widespread in Mexico. In some localities the habitat remains relatively well-preserved. The only protected area in Mexico where the species is known to occur is the Omiltemi State Ecological Park, in Guerrero. However, in Oaxaca, some localities are found in forest protected by local communities, where people are responsible for its surveillance.

Specimens examined: MEXICO. Chiapas: municipio Chanal, 26 Apr. 1961, R. Alava s.n. (AMES!, UCJEPS!, K, MO): municipio Las Rosas, along Las Rosas road, 8 Dec. 1966, R. McCullough 1776 (SEL). Unknown locality, cultivated in Moxviquil, R. Solano s.n. (OAX(photo)!). Unknown locality, M. A. Soto s.n. (AMO(photo)!). Colima: municipio Comala, System of volcano of Colima, barranca Delgado, SW of Hacienda San Antonio, 13 Apr. 1935, O. Nagel sub E. Östlund 4040 (AMES!). Guerrero: municipio Chilpancingo de los Bravo, near Santa Barbara, SW of Chilpancingo, 12 May 1934, J. González sub E. Östlund 1668 (AMES!); S of Chilpancingo, cumbre de Joveritos, 19 Oct. 1936, J. González sub E. Östlund 3257 (AMES!); Omiltemi, 3 Aug. 1967, M. Sousa 3147 (MEXU!). Jalisco: municipio Mascota, between El Pantanal and Juanacatlán, R. González T. 1182 (AMO(drawing)!). Mexico: municipio Ocuilan de Arteaga, Chalmita, 10 Aug. 2007, H. Nava-Bernal 119 (AMO!). Municipio Valle de Bravo, Los Saucos, D. Szeszko s.n. (AMO(photo)!). Michoacan: municipio Morelia, al S de Morelia camino Santa María-San Miguel del Monte, R. Jiménez 1044 (AMO!). Municipio Zinacueretiro, Pedregal del Corú, 13 Aug. 2008, J. Valdéz s.n. (OAX!). Oaxaca: municipio Juxtlahuaca, Yuvi Ka’nu, al SW de Coicoyán, 11 Aug. 1989, A. de Avila 651 (MEXU!). Municipio Putla Villa de Guerrero, 1 km al S desviación a Juxtlahuaca viniendo de Tlaxiaco, 30 Jul. 1983, R. Torres 3360 (MEXU!). Municipio San Pedro Tidaa, paraje Nanua, 8 Nov. 2013, R. Solano 4141 (OAX!).Municipio Santa Catarina Juquila, Sierra d’Oajaxa, Juquila, 1840, Galeotti 45 (W!). Municipio Santiago Comalteec, km 114 highway 125 (Oaxaca-Tuxtepec), 15 Jan 1975, E. W. Greenwood s.n. (AMO(photo)!). Veracruz: municipio Huayacocotla, 25 Apr. 1971, R. Hernandez 1200 (F! MEXU!).

Naturalista observations: MEXICO. Guanajuato: municipio Jerécuaro, Sierra de Puruagua, 6 Oct. 2020, M. Lugo (https://www.naturalista.mx/observations/64373803); Sierra de Puruagua, 23 Feb. 2021, M. Lugo (https://www.naturalista.mx/observations/70801556). Guerrero: municipio Chilpancingo de los Bravo, Jan. 2019, E. Salmerón Barrera (https://www.naturalista.mx/observations/108158947). Municipio General Heliodoro Castillo, May 2021, E. Salmeron Barrera (https://www.naturalista.mx/observations/112225173). Michoacán: municipio Erongarícuaro, 9 Apr. 2023, “Toky Irekua Ka Huarikua” (https://www.naturalista.mx/observations/154386834).

Anathallis oblanceolata (L.O.Williams) Solano & Soto Arenas, Icon. Orchid. 5-6: x. 2003

≡ Pleurothallis oblanceolata L.O. Williams, Bot. Mus. Leafl. 12(7): 241-243. 1946.

≡ Specklinia oblanceolata (L.O.Williams) Luer, Monogr. Syst. Bot. Missouri Bot. Gard. 95: 262. 2004

≡ Panmorphia oblanceolata (L.O.Williams) Luer, Monogr. Syst. Bot. Missouri Bot. Gard. 105: 169. 2006

≡ Trichosalpinx oblanceolata (L.O.Williams) Archila, Revista Guatemalensis 17(1): 72. 2014(2015).

TYPE:MEXICO: Oaxaca, In damp forests on trees, Pacific side, river valley Copalita, northwest of Pluma Hidalgo, 1000-1100 m, 1 Sept. 1937, O. Nagel & J. González sub E. Östlund 6456 (Holotype: AMES-74507!; isotypes: F-46440 ! S, G-7000!).

Rhizomatous, erect herb, up to 5 cm tall. Roots 0.6-1.0 mm diameter. Rhizome 4-7 mm long between adjacent stems, 1 mm diameter. Stems 2.5-10.0 mm long, 0.8-1.0 mm diameter, the annulus 1.5-3.0 mm below the apex. Leaf 18-45 × 4-7 mm, fleshy, oblanceolate, rounded, gradually attenuate toward the base into a conspicuous, channeled petiole. Inflorescence equal to or shorter than the leaf, 15-24 mm long; peduncle 6-13 mm long, 0.4-0.5 mm diameter, the base covered by a spathaceous bract up to 4 mm long, with 2 additional obliquely tubular, obtuse overlapping bracts, 1-2 mm long; rachis 5-8 mm long, with 2 successive flowers. Floral bracts 1.5-2.0 mm long, covered with reddish glandular-pilose trichomes. Flowers 3.7-5.0 mm high, 2 mm wide, sepals and petals bright yellowish, sometimes brownish purple tinged toward their apices and along the mid-vein, lip purple, column yellow, anther purple. Sepals conduplicate, 3-veined; dorsal sepal 4.5-5.0 × 1.5-1.8 mm, lanceolate, acute; lateral sepals 4.0-4.7 mm × 1.4-1.5 mm, lanceolate, oblique acute, shortly apiculate. Petals 3.0-3.8 mm × 0.7-0.9 mm, falcate-lanceolate, long acuminate, marginally erose-papillose, 1-veined. Lip 2.7-3.1 × 0.7-1.0 mm, entire, lanceolate-ligulate, rounded, 3-veined, glandular-postulate, longitudinally sulcate, with a basal low callus; the base with a pair of protuberances and a claw 0.3 × 0.3 mm. Column 1.7-2.4 mm long, 0.7-0.9 mm wide, wings oblong, marginally lacerate, clinandrium serrulate, foot column 0.6-0.7 mm long. Anther 0.8 mm long and wide, ovoid. Pollinia 0.8 mm long, longitudinally cleft. Ovary 0.8-1.5 mm long, pedicel 1.5-6.5 mm long. Capsule 7.5 mm long, 4.2 mm diameter. (Fig. 10 - 12).

Distribution: Endemic to México. It grows at Meridional and Trans-isthmic Highlands floristic provinces in Guerrero, Jalisco, Mexico, Michoacán, Oaxaca, Puebla, and Veracruz states. The accepted distribution model for A. oblanceolata yields a predicted AUC = 0.846, with the most influential variables being maximum temperature of the warmest month (63.6%), mean annual temperature (10.8%), and mean diurnal temperature range (8.1%.) The model identified four primary areas with the highest probability of distribution: Transverse Volcanic System (México, Michoacan, Morelos), Northern Highlands of Oaxaca, Southern Highlands of Oaxaca, and Chiapas Highlands, where the species has not yet been recorded. For A. oblanceolata, the potential distribution was estimated to be 116,517 km², equivalent to 5.93% of Mexico’s total territory (Fig. 13).

Habitat: Epiphyte or lithophyte, in oak and cloud forests, at elevations ranging from 1100 to 2250 m.

Phenology: It flowers in August-October, with fruits ripening in October.

Taxonomic notes: Anathallis oblanceolata is distinguished by its minute rhizomatous habit, oblanceolate, erect leaves with a well-defined petiole, floral bracts covered with reddish trichomes, and lip longer than the column (Fig. 10 - 12). It is most similar to Anathallis minutalis, as was noted by Williams (1946, 1951). However, it differs by its creeping habit (vs. erect), orbicular-elliptic, subsessile, fleshy-thickened leaves (vs. oblanceolate, long petiolate, and fleshy leaves), ovate, acute dorsal sepal (vs. lanceolate, acute), ovate-lanceolate lateral sepals (vs. lanceolate), and oblong-pandurate, acute lip (vs. lanceolate-ligulate, rounded).

This species was described in 1946 from a specimen collected in 1937 in Pluma Hidalgo, Oaxaca (Fig. 14-15A). However, the oldest known specimen dated almost seventy years earlier from Mirador, Veracruz, it was collected by Z. Kienast and is in W (Fig. 15B), where originally was labeled as Pleurothallis crassifolia and later as P. minutalis. This reflects that since the 19th century, there has been confusion in including specimens of what is now A. oblabcelata within A. minutalis. Luer (1975) mistakenly treated Pleurothallis oblanceolata as a synonym of P. minutalis; also, it appears that the Luer’s description for P. minutalis was based on a specimen of A. oblanceolata, as the accompanying illustration exhibits characteristics consistent with this species. This situation may have led to William’s plant being misidentified as A. minutalis, resulting in herbarium collections erroneously bearing this name (or one of its nomenclatural synonyms) for specimens that belong to A. oblanceolata. This also led to the inclusion of A. oblanceolata specimens in the description of A. minutalis in treatments by García et al. (2003) and Solano (2008a). A recent review of herbarium and alive material has allowed for the clear differentiation of the two species here.

Anathallis oblanceolata was previously considered a micro-endemic species from Southern Oaxaca, where the original vegetation has been altered by agroecological practices, and it was known from only a few sightings. Consequently, it was included as a species at risk (SEMARNAT 2019) and considered as extinct in the wild by Soto-Arenas, Solano & Hágsater (2007). It was the fourth species belonging to Anathallis to be reported for Mexico. Historically, the taxon has only been documented from Oaxaca state (Soto-Arenas 1988, Salazar 2013, Solano et al. 2016). However, Williams (1951) erroneously reported its presence in Chiapas, an error perpetuated by Espejo-Serna & López-Ferrari (1998) and Villaseñor (2016). The drawing of A. minutalis in García et al. (2003) indeed correspond to A. oblanceolata. The presence of A. oblanceolata in Guerrero, Jalisco, Mexico, Michoacán, Puebla, and Veracruz states is reported here for the first time, based on specimens previously confused with A. minutalis.

Conservation status: In the four criteria of the MER evaluation, the species obtained the following scores: A) geographic distribution = 0.3636, B) habitat characteristics = 0.3333, C) intrinsic biological vulnerability = 0.1739, and D) impact of human activity = 0.4000; resulting in a total score of 1.2708. Since this value is ≥1.0 and <1.5, and the sum of criterion D is ≥ 0.3, the corresponding risk category is Subject to Special Protection (Pr). Anathallis oblanceolata had previously been classified as an endangered species (P) (SEMARNAT, 2019), largely due to its apparent status as a microendemism with high habitat specificity (Soto-Arenas et al. 2007). However, the MER assessment demonstrates that the taxon must be reclassified to another lower-risk category. Although there are no populations within natural protected areas, the species has widespread distribution in Mexico, and several localities do not face severe habitat threats. One locality in Guerrero is situated in the Omiltemi State Ecological Park. Additionally, in Oaxaca, some populations are located in forest protected by local communities, where community people are responsible for its surveillance and protection.

Specimens examined: MEXICO. Estado de Mexico: Municipio Donato Guerra, D. Szeszko-Fabila s.n. (AMO(photo)!). Municipio Tenancingo, M. A. López s.n. (Amo(photo)!). Guerrero: municipio Chilpancingo de los Bravo, Omiltemi, G. Salazar s.n. (AMO photo!). Jalisco: municipio Tecalitlán, near Ciudad Guzmán, cañada del Laurel, cerro de La Ribera, 19 Sep. 1936, O. Nagel & J. Navarro sub. E. Östlund 6338 (AMES!, CAS! SEL!). Michoacan: municipio Erongarícuaro, en el pedregal de Tócuaro, 15 Oct. 1996, E. Pérez 3511 (IEB!), 22 Aug. 1997, E. Pérez 3694 (IEB!); Pedregal de Tócuaro, Municipio Pátzcuaro, near Patzcuaro, 6000 ft, cultivated in Cleremont, CA, 22 Feb. 1979, W. Gann s.n. (SEL!). Oaxaca: municipio San Jerónimo Coatlán, 7 km al NE del campamento maderero Cerro Sol brecha a Progreso, 6 Oct. 1988, A. Campos 2599 (MEXU!). Municipio Santa Catarina Lachatao, 26 Aug. 2017, J. Santiago s.n. (MEXU!). Puebla: Municipio Ayotoxco de Guerrero, 31 Aug. 2019, G. Salazar s.n. (MEXU!). Municipio Tetela de Ocampo, cañon de Escahuasco, 15 Oct. 1995, A. Espejo et al. 5366 (UAMIZ!). Veracruz: (municipio Totutla) Mirador, Huatusco, May 1878, Z. Kienast s.n. (W!).

Naturalista observations: MEXICO. Jalisco: Concepción de Buenos Aires, entre Concepción de Buenos Aires y los Aguares, 4 Aug. 2013, J. Moreno (https://www.naturalista.mx/observations/2867438). Oaxaca: Santa Catarina Lachatao, 15 Aug. 2018, B. Nuñez-Oberg (https://www.naturalista.mx/observations/15713121).

Anathallis sertulorioides (Sw.) Pridgeon & M.W.Chase, Lindleyana 16(4): 250. 2001.

≡ Epidendrum sertularioides Sw., Prodr. 122. 1788

≡ Dendrobium sertularioides (Sw.) Sw., Nova Acta Regiae Soc. Sci. Upsal., ser. 2, 6: 83. 1799.

≡ Pleurothallis sertularioides (Sw.) Spreng., Syst. Veg. (Sprengel) 3: 721. 1826.

≡ Specklinia sertularioides (Sw.) Lindl., Gen. Sp. Orchid. Pl. 8. 1830.

≡ Humboltia sertularioides (Sw.) Kuntze, Revis. Gen. Pl. 2: 668.1891.

≡ Specklinia sertularioides (Sw.) Luer, Monogr. Syst. Bot. Missouri Bot. Gard. 95: 263. 2004, nom. illeg.

≡ Panmorphia sertularioides (Sw.) Luer, Monogr. Syst. Bot. Missouri Bot. Gard. 105: 174-176, f. 145. 2006.

≡ Trichosalpinx sertularioides (Sw.) Archila, Revista Guatemalensis 17(1): 72. 2014(2015).

TYPE: JAMAICA: unknown locality, “provenit in arboribus densis antiques montium”, Swartz s.n. (Sintypes in BM-82293!, G-168992!, S-R1968!, S-R-1969! W-16974!).

Syn.: Pleurothallis tenuissimaRchb. f., Linnea 18: 399-400. 1844

= Humbodltia tenuissima (Rchb.f.) Kuntze Revis. Gen. Pl. 2: 668.1891.

TYPE: MEXICO: (Chiapas), unknown locality, “Tropiches Mexiko”, Leibold. Lectotype designed here: F.E. Leibold 620 (W!, drawings at AMES-74790!, AMES-74791).

Syn.: Pleurothallis trichopoda A.Rich. & Galeotti, Ann. Sci. Nat., Bot. sér. 3, 3: 17. 1845, non Rchb.f 1856, nom. illeg.

= Humboldtia trichopoda (A.Rich. & Galeotti) Kuntze, Revis. Gen. Pl. 2: 668. 1891.

TYPE: MEXICO: Fl. jaunes clair, chênes à 2500- 4000, Cordillera, Veracruz, 1840, Juliet 1840. Lectotype here designated: H.G. Galeotti 5166 (W-12717!; isolectotypes: AMES! BR!, G-168983!, K).

Repent, erect herb, up to 4 cm tall, including the inflorescence. Rhizome 2-7 mm long between adjacent stems, 0.6 mm diameter. Roots 0.5-0.6 mm diameter. Stems 2.5-7.0 mm long, 0.5-0.7 mm diameter, the annulus 0.7-1.5 mm below the apex. Leaves 10-33 × 2-4 mm, fleshy, linear-oblanceolate, rounded, attenuate toward the base into a channeled petiole. Inflorescence 1.0-3.5 cm long, 1-flowered; peduncle 1.5-2.3 cm long, covered at the base by a spathaceous bract 1 mm long, with 1 additional tubular bract 1.0-1.7 mm long. Floral bract tubular, obtuse, shorth apiculate, 1-2 mm long. Flowers 3.7-5 mm tall, 3.0-3.5 mm long, yellowish green, pointed upward. Sepals conduplicate, 1-nerved; dorsal sepal 4.0-5.3 × 1.5-1.7 mm, triangular-lanceolate, slightly falcate, acute, incurved at the apex; lateral sepals 3.7-5.0 × 1.2-1.4 mm, obliquely lanceolate, acute, deflexed near the middle, gibbous at their bases. Petals 3.2-3.9 × 0.8-1.1 mm, falcate-lanceolate, long acuminate, 1-nerved. Lip 2.7-3.0 × 0.6-0.9 mm, shortly 3-lobed, linear-lanceolate, rounded, 3-nerved, truncate at the base, margins revolute towards the apex, longitudinally channeled, with two mammillae calli at the base; lateral lobes at the middle, subtriangular, rounded, incurved, 0.25 × 0.30 mm. Column 1.8-2.0 mm long, 0.6 mm wide, arching, wings marginally dentate, clinandrium dentate, foot column shorter than the body. Anther 0.3-0.4 mm long and wide, globose. Pollinia 0.2-0.3 mm long, piriform. Ovary 1.7-2.5 mm long, pedicel 2-7 mm long. Capsule 6-7 mm long, 2.4-2.8 mm in diameter (Fig. 16-17).

Distribution: Mexico, Belize, El Salvador, Guatemala, Honduras, Nicaragua, Costa Rica, Cuba, and Jamaica. In Mexico it grows along the Gulf of Mexico Coast and Yucatan Peninsula floristic provinces, in Chiapas, Oaxaca, Puebla, Tabasco, and Veracruz. The accepted distribution model for A. sertularioides yields a predicted AUC = 0.968, with the most influential variables being annual precipitation (53.7%), precipitation of the coldest month (17.9%), and annual temperature range (9.3%). The model predicted four primary areas with the highest probability of distribution: the Lancandon forest (Chiapas), Chinantla-Chimalapas-Los Tuxtlas (Oaxaca, Veracruz), Pluma Hidalgo (Southern Oaxaca), and Northern Highlands of Puebla. For A. sertularioides, the potential distribution area was estimated to be 97,409.85 km², equivalent to 4.96% of Mexico’s total territory (Fig. 18).

Vásquez & Ibisch (2000) reported the species from Bolivia as P. sertularioides. However, this report was likely based on a similar species, or a taxon from Madisonia Luer, as delimited by Smidt et al. (2021). This genus encompasses Amazonian plants with habit and floral morphology similar to P. sertularioides. However, Madisonia is the sister group of Octomeria R.Br., and both genera occupy a basal position within Pleurothallidinae.

Habitat: Epiphyte in evergreen rain forest, semideciduous tropical forest, and tropical oak forest, at elevations ranging 120 to 950 m. It can be locally abundant, and creeping plants commonly form carpets on the tree limbs.

Phenology: It flowers from January to September, with fruits ripening from November to February.

Taxonomic notes: Anathallis sertularioides is characterized by its long repent habit, abbreviated stems, linear-oblanceolate leaves, an inflorescence reduced to one functional flower, lanceolate sepals, falcatelanceolate petals, and 3-lobed, linear-lanceolate lip (Fig. 16-17). The most similar species is A. oblanceolata, but it can be differentiated by its shorter rhizome, broader leaves (4-7 mm wide vs. 2-4 mm wide), inflorescence with 2 successive flowers (vs. 1 functional flower), and a single lip (vs. shortly 3-lobed). Anathallis yucatanensis is similar too, it differs by its raceme longer than the leaf (vs. as long as the leaf), an inflorescence with 3-6 simultaneous flowers (vs. 1 functional flower), yellowish flowers (vs. bright yellowish and purple tinged), long acuminate petals (vs. long acute), and a single lip (vs. shortly 3-lobed).

Apparently, the plants from the Antilles are very similar to those from the mainland; maybe the type specimen (Fig. 19) has broader leaves and slightly smaller flowers. Unfortunately, it is difficult to evaluate these differences when this form is known from very few specimens. The type of P. tenuissima (Fig. 20) has longer and narrower leaves; otherwise, it seems to be conspecific with A. sertularioides. Pleurothallis trichopoda was described from a specimen collected by Galeotti (Fig. 21) in Veracruz, probably in the vicinity of El Mirador-Totutla, where other collections by the same collector originated. Specimens from this same region are morphologically indistinguishable from those from other regions of Mexico for this species.

In the past, Pleurothallis sertularioides var. trinitensis Griseb. has been considered under the synonym of P. sertularioides (Cogniaux 1910). However, it has a 2-3 flowered inflorescence (vs. 1-flowered), with distant, pale purple flowers (vs. yellowish green) along the rachis, with a purple lip (vs. yellow), leading to its recognition as a different species, Pleurothallis trinitensis (Griseb.) Carnevali and Romero-González (Romero & Carnevali 2000). This plant is very similar to Pleurothallis spiculifera Lindl., both names may turn out to be conspecific, which is now included in Madisonia.

This species was originally described by Swartz (1788) as Epidendrum sertularioides from a specimen collected in Jamaica (Fig. 19). McLeish et al. (1995) and Luer (2006, 2023) pointed out that the holotype of Epidendrum sertularioides is in S, but neither of them specified which specimen it is. However, in the protologue, Swartz did not make any reference to a type specimen. Specimens collected by Swartz in Jamaica and labelled as Specklinia sertularioides have been located in BM, G, S, and W, which are designated here as syntypes. On the other hand, Luer (2006) designated holotypes for the two heterotypic synonyms of this species. For P. tenuissima, Leibold 620 at W, with isotypes at AMES and BR, and for P. trichopoda, Galeotti 5166 at W. Although the protologue of P. tenuissima mentioned Leibold as a collector of the plant from which Reichenbach published the name, it did not specify the collection number. Meanwhile, in the protologue of P. trichopoda there wasn't any indication of a type by Richard and Galeotti. According to art. 9.1 of Shenzhen Code (Turland et al. 2018), a “holotype of a name of a species… taxon is the one specimen or illustration either (a) indicated by the author(s) as the nomenclatural type or (b) used by the author(s) when no type was indicated”; while art. 9.3 states that a “lectotype is one specimen or illustration designated from the original material … if the name was published without a holotype, or if the holotype is lost or destroyed”. Thus, specimens Leibold 620 and Galeotti 5166 don’t turn out to be the holotypes for P. teniussima and P. trichopoda, respectively. They should be designated as their lectotypes, as proposed here.

This species was originally described as Epidendrum sertularioides from Jamaica. Later, it was described again twice, almost simultaneously from Mexican specimens, as Pleurothallis tenuissima (Fig. 20) by Reichenbach (1844), and Pleurothallis trichopoda (Fig. 21) by Richard & Galeotti (1845). Therefore, this species was the second documented in Mexico for what now is Anathallis. However, both Reichenbach and Richard & Galeotti were unknown by botanists for almost a century. So, the first Mexican report of this species was published by Williams (1951), based on a specimen collected in Oaxaca. In Mexico the species has been reported as Pleurothallis sertularioides by Soto-Arenas (1988), Espejo-Serna & López-Ferrari (1998), and Martínez et al. (1994); as Panmorphia sertularioides by Luer (2023), and as Anathallis sertularioides by Salazar (2013), Noguera-Savelli & Cetzal-Ix (2014), Villaseñor (2016), and Krömer et al. (2020).

Conservation status: In the four criteria of the MER evaluation, the species obtained the following scores: A) geographic distribution = 0.4545, B) habitat characteristics = 0.2222, C) intrinsic biological vulnerability = 0.1739, and D) impact of human activity = 0.3000; resulting in a total score of 1.1506. Since this value is ≥1.0 and <1.5, and the sum of criterion D is ≥ 0.3, the corresponding risk category is Subject to Special Protection (Pr). This species is an abundant epiphyte in the lowland tropical forest. Some populations are protected in the Calakmul (Campeche), Lacan-Tun (Chiapas), and Montes Azules (Chiapas) biosphere reserves, as well in Bonampak natural monument (Chiapas). However, the species’ habitat is located in the region where the Mexican government is building the Tren (Train) Maya project. Undoubtedly, the edge effect associated with the railway tracks’ layout, as well as the development of tourist infrastructure, and the increase in the human population in the region, will negatively affect the forests where the taxon currently grows.

Specimens examined: MEXICO. Chiapas: municipio Ocosingo, a 6.2 km al NO de Crucero San Javier, 20 Jun. 2003, G. Aguilar 7168 (MEXU!); 0.4 km al N del banco de grava de San Javier, 23 Nov. 2002, D. Álvarez 2473 et al. (MEXU!); Crucero Corozal, 10 Jun. 1984, E. Martínez 6471 (MEXU!); en Crucero Corozal, sobre la Carretera Fronteriza del Sur, 17 Jun. 1984, E. Martínez 6579 (MEXU!); a 4 km al S de Frontera Corozal, sobre el río Usumacinta, 29 May 1985, E. Martínez 12343 (MEXU!, MO!); ojo de agua de San Javier, 23 km al SE de Nuevo Guerrero camino a Boca Lacantum, 29 Jan. 1986, E. Martínez 16932 (MEXU!, TEX!, XAL(mixed with A. lewisiae)!), E. Martínez 25043 (MEXU!); ojo de agua de San Javier, E. Martínez 24983 (AMO! MEXU!); ojo de agua de San Javier, E. Martínez 25034 (AMO!); porción N de la Omega, Monumento Natural Yaxchilán, 10 Feb. 1999, J. Meave 2260 (MEXU!); 2.8 km al N de la Estación Biológica de Chajul, 26 Jun. 1999, S. Sinaca 2725 (MEXU!). Municipio Venustiano Carranza, 3 mi S of Aguatenango along road to Pinola-Las Rosas, 15 Jul. 1966, D. E. Breedlove 14546 (F!, MICH!, TEX!). Oaxaca: municipio Mazatlán Villa de Flores, near Mazatlan, 30 Jun. 1960, T. MacDougall s.n. (AMES!). Municipio San Pedro Sochiapan, finca Union Francesa, near Rio Blanco, 28 Jun. 1939, R. E. Schultes 725 (AMES!); road near San Pedro Sochiapam, 1 Jul. 1939, R. E. Schultes 758 (AMES!). Puebla: municipio Ayotoxco de Guerrero, Cuauhtémoc, en la junta del río Atekakalach con el río Apulco, 2 Jul. 2016, M. Jimémez & M. Gorostiza 31388 (MEXU!); Tabasco: municipio Huimanguillo, a orillas de la laguna del Rosario, 7 Feb. 1987, M. A. Magaña 1738 et al. (MEXU!, UJAT!). Veracruz: municipio Totutla, Zacuapan, 20 Aug. 1933, O. Nagel sub E. Östlund 2654 (AMES! sketch in AMO!); El Mirador, 25 Jun. 1977, F. Ventura 14158 (AMO! ASU!, CAS!, ENCB!, SEL!). Municipio Xalapa, E. Pérez sub R. Jiménez 1129 (AMO!).

Naturalista observations: MEXICO. Puebla: municipio Cuetzalan del Progreso, orillas del río Tecolutla, cerca de Zacatipan, 31 May 2015, R. Alvarez-Mora (https://www.inaturalist.org/photos/116697164).

Anathallis yucatanensis (Ames & C.Schweinf.) Solano & Soto Arenas, Icon. Orchid. 5-6: x 2003.

≡ Pleurothallis yucatanensis Ames & C.Schweinf., Bot. Mus. Leafl. 1(2): 4-5. 1932.

≡ Specklinia yucatanensis (Ames & C.Schweinf.) Pridgeon & M.W.Chase Lindleyana 16(4): 260. 2001.

≡Trichosalpinx yucatanensis(Ames & C.Schweinf.) Archila, Revista Guatemalensis 17(1). 72. 2014(2015).

TYPE:MEXICO: Yucatan (Peninsula), Campeche, (Escárcega municipality, La) Tuxpeña, 230 m, 8 November 1931, C.L. Lundell 912 (Holotype: AMES-74877!; isotypes: F-46445! MICH1115262! US-93716(photo in MEXU)!).

Repent, erect herb, up to 4 cm tall, including the inflorescence. Roots 0.5 mm diameter. Rhizome 1.5-3.5 mm long, 0.6 mm diameter. Stems 2-4 mm long, 0.4-0.5 mm diameter, the annulus close to the apex. Leaves 8-20 × 3.0-4.5 mm, fleshy, oblanceolate, rounded, gradually attenuate toward the base into a channeled petiole. Inflorescence up to 3.5 cm long; peduncle 1.5-2.3 cm long, covered at the base by a spathaceous bract 0.7-0.8 mm long, with 2-3 additional tubular bracts, 0.8-1.5 mm long, rachis up to 10 mm long, with 3-6 simultaneous flowers. Floral bracts 0.7-1.0 mm long. Flowers 2.8-3.5 mm tall, erect or ascendent, subcongested, yellowish or whitish yellow. Sepals conduplicate, slightly fleshy, 3-nerved; dorsal sepal 2.5-3.6 × 1.0-1.2 mm, lanceolate, acute; lateral sepals 2.3-3.4 × 0.8-1.0 mm, obliquely lanceolate, long acute, gibbous at their bases. Petals 2.5-3.9 × 0.5-0.9 mm, linear-lanceolate, oblique, long acute, slightly fleshy, 1-nerved. Lip 1.2-1.6 × 0.4-0.6 mm, single, oblong, rounded, recurved, and emarginate at the apex, 3-nerved, the margins upward at the basal middle, with two submarginal and raised calli at the middle, channeled between them. Column 1.0-1.8 mm long, wings subquadrate, marginally dentate and triangular at the apex, clinandrium dentate; foot column longer than the body. Anther 0.3 mm long and wide, globoseovoid. Pollinia 0.2 mm long, piriform. Ovary 0.5-0.9 mm long, pedicel parallel to the rachis, 1.0-1.5 mm long. Capsule not seen. (Fig. 22-23).

Distribution: Mexico, Belize, Guatemala, and Nicaragua, probably in Honduras. In Mexico it grows along the Gulf of Mexico Coast and Yucatan Peninsula floristic provinces, in Campeche, Chiapas, Oaxaca, Quintana Roo, Tabasco, and Veracruz. The accepted distribution model for A. yucatanensis yield a predicted AUC = 0.853, with the most influential variables being Mexican digital elevation model (69.5%), mean temperature of the warmest quartet (20.0%), and isothermally (4.3). The model predicted four primary areas with the highest probability of distribution: Southern Yucatan Peninsula (Campeche, Quintana Roo), the Lancandon forest (Chiapas), Chinantla-Los Chimalapas (Oaxaca), and Los Tuxtlas (Veracruz), where the species has not yet been recorded. For A. yucatanensis, the potential distribution area was estimated to be 56,145.79 km², equivalent to 2.86% of Mexico’s total territory (Fig. 24).

Habitat: Epiphyte in evergreen tropical forest, semideciduous tropical forest, and oak forest, at elevations ranging from 150 to 300 m.

Phenology: It flowers from October to December, with fruits ripening in December.

Taxonomic notes: Anatallis yucatanensis is characterized by its small and creping habit, a raceme longer than the leaf, with 3-6 yellowish flowers opening simultaneously and an entire, oblong lip (Fig. 22-23). The most similar species is A. sertularioides, but it has a relatively larger habit, an inflorescence nearly equal in length to the leaf (vs. longer than the leaf), with only one functional flower (vs. 3-6 successive flowers), and a shortly 3-lobed lip (vs. entire lip). Luer (1975) considered this species similar to Pleurothallis grobyi Bateman ex Lindl., which is now under Specklinia (Luer, 1986). Therefore, when Pridgeon & Chase (2001) resurrected Specklinia, they transferred P. yucatanensis as part of it. However, A. yucatanensis shares similar habit and a set of floral traits with A. sertularioides and other Anathallis members, justifying its reclassification accordingly.

Hamer (2001) reported this species for Nicaragua based on a specimen from Jinotega with an elevation of 1170 m (Heller 11011). However, the specimen may have been misidentified, as Anathallis yucatanensis is a plant of the evergreen tropical forest from low areas along the coastal plains of the Gulf of Mexico and the Caribbean Sea.

This species was the third Anathallis described from Mexico, as Pleurothallis yucatanensis, from a specimen collected in Campeche in 1931 (Fig. 25). Subsequently, it has been documented in the country as P. yucatanensis by Williams (1951), Soto-Arenas (1988), Martínez et al. (1994), Espejo-Serna & López-Ferrari (1998), Hágsater et al. (1998), and Carnevali et al. (2001); as Anathallis yucatanensis by Salazar (2013), Noguera-Savelli & Cetzal-Ix (2014), Villaseñor (2016), and Krömer et al. (2020); and as Specklinia yucatanensis by Luer (2023). A taxonomic treatment for this species was published by Solano (2008b).

Conservation status: In the four criteria of the MER evaluation, the species obtained the following scores: A) geographic distribution = 0.4545, B) habitat characteristics = 0.2222, C) intrinsic biological vulnerability = 0.1739, and D) impact of human activity = 0.3000; resulting in a total score of 1.1596. Since this value is ≥1.0 and <1.5, and the sum of criterion D is ≥ 0.3, the corresponding risk category is Subject to Special Protection (Pr). This species is a common epiphyte in Mexican lowland evergreen tropical forests, where it can be locally abundant. Some populations are protected in Calakmul (Campeche), Montes Azules (Chiapas), Lacan-Tun (Chiapas) and Sian Kaan (Quintana Roo) biosphere reserves, as well as in natural monument Yaxchilan (Chiapas). However, it’s noting that the species’ habitat lies within the region where the Mexican government is currently constructing the Tren (Train) Maya project. Undoubtedly, the associated edge effects from the railway tracks’ layout, the development of tourist infrastructure, and the increase in the human population in the region will likely have negative impacts on the forests where this taxon currently thrives.

Specimens examined: MEXICO. Campeche: municipio Calakmul, southern Campeche, collected Nov. 1994, pressed 21 Nov. 1994, J. Andrews ex M. Sarmiento s.n. (AMO!); 200-300 m de Becán, 3 Feb. 1998, G. Carnevali 4958 et al. (CICY); a la orilla de la carretera Xpujil-Dzibalchén, al N de La Nueva Vida, 13 Oct. 1997, E. Lira 120 (MEXU!); 500 m al N del poblado 11 de Mayo, 15 Oct. 1997, E. Madrid 165-C (MEXU!); 10 km al SE de Dos Naciones, camino a El Civalito, 3 Oct. 1997, E. Martínez 29320-A et al. (MEXU!); 6 km al NW de Dos Naciones, camino a ranchería El Sacrificio, 27 Oct. 1997, E. Martínez 29749 et al. (MEXU!); 9 km al SE de Dos Naciones camino a El Civalito, 4 Dec. 1998, E. Martínez 31422 (MEXU!); a 1 km al E de 16 de Sep., 6 Dec. 1998, E. Martínez 31543 (MEXU!); 3 km al E de La Nueva Vida camino a La Mancolona, 7 Dec. 1998, E. Martínez 31616 et al. (MO!, TEX!), E. Martínez 31618 et al. (MEXU!, TEX!); 25 km al S de Xpujil, carretera a Laguna Alvarado, 5 May 1998, G. Carnevali & Ramírez 5339 (CICY); 18.7 Km al O de Xpujil, J. C. Soto 21656 (MEXU!). Torre, 35 km al norte de la zona arqueológica, 23 Nov. 1999, D. Méndez & B. Christopher 84 (LSU!). Palizada, El Vapor, 25-28 Jul. 1939, E. Matuda 3895 (MEXU!). Chiapas: municipio Ocosingo, Campamento COFOLASA, a 24 Km al SE de Crucero Corozal, sobre camino Palenque-Boca Lacantum, 7 Dec. 1984, E. Martínez 9226 (MEXU!), E. Martínez 9269 (MEXU!), E. Martínez 25048 (MEXU!); porción N de la Omega, Monumento Natural Yaxchilán, 12 Dec. 1997, A. Rincón 850 (MEXU!). Oaxaca: municipio Santa Maria Chimalapas, Hernández 946 (CHAPA!). Quintana Roo: municipio Othon P. Blanco, 5 km al N de La Unión, 5 Dic. 1997, G. Carnevali 4894 (CICY!); ejido Caobas, sabana del Jaguactal, G. Carnevali 5298 et al. (AMES! CICY!); Sabana El Jaguactal, 9.5 km al E de carr. hacia Tres Garantías, G. Carnevali 5292 (CICY!); El Aguacate, ejido Tres Garantías, carr. a Dos Aguadas, 28 Mar. 1999, L. Ibarra sub E. Hágsater 12216 (AMO!); 9 km antes del Ejido La Unión, 9 May 1981, E. Ucán & S. Flores 955 (CICY!); Ejido Caobitas, 16 May 1984, E. Ucán et al. 3369 (XAL! CICY). Tabasco: Balancán, carretera no. 25, a 3 km sobre la EWO a la carretera no. 20, P.E. Valdivia 2081 (XAL!). Veracruz: Uxpanapa, P.E. Valdivia 973-B (XAL!).

Naturalista observations: MEXICO. Campeche: municipio Calakmul, Apr. 2023, I. Arellano (https://www.inaturalist.org/observations/166199300); Calakmul, 18.431152 N, -89.504923 W, Oct. 2021, R. Vela (https://www.inaturalist.org/observations/106721409); Calakmul, 18.182517 N, -89.250958, 21 Oct. 2021, D.A. Burgos-Mex (https://www.inaturalist.org/observations/104950069).

New Combination and a Note in Lankesteriana

To maintain the circunscription of Anathallis in Mexico, the following combination is required in the Lankesteriana genus.

Lankesteriana greenwoodii (Soto Arenas & Salazar) Solano comb. nov.

Basionym: Anathallis greenwoodii Soto Arenas & Salazar, Icon. Orchid. 5-6: t. 519. 2003.

TYPE: MEXICO: Oaxaca, Distrito Ixtlán, km 46.7 del camino Ixtlán de Juárez-Talea de Castro, en la desviación a Tanetzé de Zaragoza y Juquila Quijanos, 25 Mar. 2000, pressed from cultivate material 19 Dec. 2001, M. Soto 9441 et al. (Holotype: AMO!; isotype: AMO!).

Taxonomic notes: Currently, this species has only been documented from Northern Oaxaca. It shares similarities with two other species: L. comayaguensis (Ames) Karremans, from Central America, and L. involuta (L.O.Williams) Karremans, from Western and Southern Mexico. While there are no available DNA accessions for this taxon to assess its phylogenetic position, its morphology suggests a closer affinity with Lankesteriana than with Anathallis. This is evident in its diminutive, creeping habit, bilabiate flowers, fused lateral sepals forming a synsepal, falcate and caudate petals, and glandular cilia along the margins of the lip (Fig. 26).

Lankesteriana haberi (Luer) Karremans, Lankesteriana 13(3): 327. 2014.

≡ Pleurothallis haberiLuer Selbyana 23(1): 36, f. 27. 2002.

≡ Anathallis haberi (Luer) Solano & Soto Arenas, Icon. Orchid. 4-5: t. 520. 2003.

≡ Specklinia haberi (Luer) Luer, Monogr. Syst. Bot. Missouri Bot. Gard. 95: 261. 2004: 261.

≡ Panmorphia haberi (Luer) Luer, Syst. Bot. Missouri Bot. Gard. 105: 158. 2004 2006.

TYPE: COSTA RICA: Alajuela, Reserva Biológica Monteverde, rio Peñas Blancas, 15 Dec. 1987, W. Haber & E. Bello 7917 (Holotype in CR!, isotype in MO).

Syn.: Lankesteriana glandulosa Archila & Szlach., Revista Guatemalensis 17(2): 73 2014(2015), nom. inval.

HOLOTYPE: GUATEMALA. Coban: Alta Verapaz, Setaña Cangüinik, 500 m, colectada por Fredy Archila, Mar. 2008, FA-s.n. (BIGU).

Taxonomic note: The online databases of Missouri Botanical Garden (http://legacy.tropicos.org), International Plant Names Index (https://www.ipni.org), Plants of the World Online (https://powo.science.kew.org/), and Karremans et al. (2021) consider L. glandulosa an invalid name. This determination is due to the authors’ failure to provide a diagnosis (in Latin or English) or reference to a previous and effective published diagnosis, thereby violating art. 38 and 39 of the Shenzhen code (Turland et al. 2018). Plants of the World Online also highlights that being an invalid name, L. glandulosa becomes an unplaced name, which cannot be considered as an accepted name or included as a synonym for another.

The specimen described by Archila (2014(2015)b, Fig. 27I ) has floral segments larger in size compared to the type and Mexican specimens of L. haberi. But apart from that, L. glandulosa proves to be indistinguishable from the latter, as observed in Luer (2002) and Solano & Soto-Arenas (2003) (Fig. 27II and 28, 29, respectively). Both exhibit a minute and caespitous habit, with abbreviated stems, obovate leaves with a well-defined petiole, successive and congested flowers at the apex of a raceme, oblong-lanceolate dorsal sepal, fused lateral sepals forming an elliptical and shortly bifid synsepal, oblong petals with an apically papillose terete tail, oblong-lanceolate, ciliate lip, and arcuate, prominently winged column, with a lacerated clinandrium. Furthermore, the distribution range of L. haberi extends from Chiapas (Mexico) to Costa Rica, encompassing elevations of 180-900 m, which includes the type locality of L. glandulosa.

Conclusions

A total of 15 Mexican species have been previously included within Anathallis. However, three of these species, namely A. dolichopus, A. platystylis, and A. scariosa, have been reassigned to Stelis. Another species, A. fuegii (Rchb.f) Pridgeon & M.W.Chase, was transferred to Specklinia. Five taxa, A. abbreviata, A. barbulata, A. comayaguensis, A. haberi, and A. involuta, have been segregated into Lankesteriana. Meanwhile, A. greenwoodi was transferred here to Lankesteriana. The remaining five species are the ones that still belong to the genus Anathallis. Table 1 provides an overview of the taxonomic history of this genus in Mexico.

The Mexican Anathallis species recognize here are A. lewisiae, A. minutalis, A. oblanceolata, A. sertularioides, and A. yucatanensis. From them, A. minutalis and A. oblanceolata are distributed along the forests of the main mountain ranges in the tropical region of the country, where their distribution sometimes overlaps. On the other hand, A. lewisiae, A. sertularioides, and A. yucatanensis are representative species found in the orchid flora of low, warm, and humid regions along the Gulf of Mexico Coast and Yucatan Peninsula. Table 2 provides a comparative summary of the morphological characteristics among these five species. Anathallis oblanceolata is re-described here based on Mexican specimens previously confused with A. minutalis. For each taxon, a risk category was proposed following the regulations applicable to wild plant species in Mexico. This allows for evaluations to be comparable to those conducted for other species in the country’s flora.

Acknowledgments

To the curators of the herbaria that facilitated the review of specimens presented in this study. To the institutions that granted permission to reproduce the digitalized images of type specimens and drawings. The financial support provided by the Mexican Comision Nacional para el Conocimiento y Uso de la Biobidersidad (CONABIO, project KT005).

Literature cited

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