<span name="style_bold">Pollen morphology in species of </span><span name="style_italic">Canna </span><span name="style_bold">(Cannaceae), and systematics implications. </span>The morphology of pollen grains of eight taxa of <span name="style_italic">Canna, C. ascendens</span>, <span name="style_italic">C. coccinea, C. compacta</span>, <span name="style_italic">C. glauca</span>, <span name="style_italic">C. indica, C. paniculata, C. variegatifolia </span>and <span name="style_italic">C. fuchsina, </span>an unpublished new species<span name="style_italic">, </span>were studied using light and scanning electronic microscopes. We used the Wodehouse technique on samples of 20 grains per specimen to measure the intine with a light microscope; and the density of spines (in 400μm<span name="style_sup">2 </span>fields) with scanning electronic microscopy. Pollen grains are spherical, echinate, omniaperturate. The sporoderm presents a very thin exine covering a thicker intine. Corrugate micro-perforate, sub-reticulate, rugate, rugulate, striate to folded, micro-striate, micro-granulate, and smooth types of the external surface of the sporoderm were found. The spines consist of exine, partially to completely covered by tryphine. The two-layered intine is the thicker part of the wall. Echinate ornamentation is a generic character in <span name="style_italic">Canna</span>, but size, surface and color of pollen walls, and density and shape of spines, are diagnostic for species. Pollen morphology supports the view of <span name="style_italic">C. indica </span>and <span name="style_italic">C. coccinea </span>as different species<span name="style_italic">. Canna fuchsina </span>grows in wild, dense colonies, in humid riverside forests from Buenos Aires and Santa Fe Provinces, Argentina; its characters suggest relationships with a not well known group of taxa, some of them hybrids, such as <span name="style_italic">C. x generalis. </span>However, as these plants showed normal, well formed grains, close to those of <span name="style_italic">C. coccinea, </span>that germinate over the stigmatic surfaces in fresh flowers, we decided to include their pollen in this study. Rev. Biol. Trop. 58 (1): 63-79. Epub 2010 March 01.that germinate over the stigmatic surfaces in fresh flowers, we decided to include their pollen in this study. Rev. Biol. Trop. 58 (1): 63-79. Epub 2010 March 01.

Canna; Cannaceae; polen; granos omniaberturados; ornamentación equinada; exina; espinas; intina; trifina; palinología