01531nas a2200157   4500008004100000245008500041210006900126260001200195300001400207490000700221520097400228100001701202700001901219700001801238856011701256       2006                        eng d00aMicrospore morphology of Isoetes species (Lycophyta) from Southern South America0 aMicrospore morphology of Isoetes species Lycophyta from Southern  c2006///  a121 - 1340 v723 aMicrospores of the 24 species of Isoetes that grow in southern South America were analyzed under a light microscope and scanning electron microscope. The microspores are monolete, elliptic in polar view, 30-40 μm long, and 20-25 μm wide. A background with various characteristics is seen on each surface. A supra-laesural expansion is present. The perispore is ornamented and has a perforated background. In section, it has a lacunose structure. The exospore is smooth, and it has a compact structure in section. The studied species could be divided into three groups by their perispore ornamentation: equinate, rugulate, and tuberculate. Microspore size was positively correlated with increasing ploidy level, and larger microspores were associated with terrestrial habitats. A convergence in ornamentation was found between spores produced by the studied species and those that grow in regions outside of the area under study. © 2006 The New York Botanical Garden.1 aMacLuf, C.C.1 aMorbelli, M.A.1 aGiudice, G.E.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-33746007149&partnerID=40&md5=89828b318fcdc3d646eb9f235b2e34ee