Monographs Details: Azolla mexicana C.Presl
Authority: Mickel, John T. & Beitel, Joseph M. 1988. Pteridophyte Flora of Oaxaca, Mexico. Mem. New York Bot. Gard. 46: 1-580.
Discussion:Type. Mexico. Schiede & Deppe  (B!); locality given is “inter Serpillo et Estero,” which is in the state of Veracruz, halfway between Veracruz and Tuxpán (A. R. Smith, 1981).
Plants flattened, dichotomously branched, 1-2 cm diam.; upper leaf-lobes imbricate, rhombic-ovate, broadly rounded to obtuse at apex, ca. 0.7 mm long, papillose on upper surface, lower lobe larger than upper, the margin purplish-tinged or hyaline; microsporocarps ca. 1 mm diam., globose; glochidia of massulae 2-6-septate; megasporocarps 0.25-0.3 mm long; megaspores pitted on basal portion.
Azolla microphylla Kaulfuss, known from Guatemala to Brazil, also has septate glochidia, but the megaspores are smooth on the basal portion.