Salvinia molesta

STEMS: with dense dark multicellular hairs. FLOATING LEAVES: 0.8-3.0 cm long, the blade elliptic-ovate to oblong-ovate and relatively flat in young plants, oblong-ovate to suborbicular and somewhat folded along the midrib in mature plants, shallowly notched at the tip, cordate at the base, the venation obscure, the adaxial trichomes to 2 mm long (Fig. 2), the 4 apical branches fused at the tip, creating the impression of an egg-beater or cage. SPOROCARPS: in chain-like clusters of 6-35 along “branches” of the submerged leaf blade, the proximal 1 or 2 slightly longer-stalked and megasporangiate, the remainder microsporangiate, 1.2-2.2 mm long, ovoid, narrowed to a short beak-like tip, pubescent with hairs similar to those of the submerged leaf. SPORANGIA: empty or the spores abortive and collapsed. 2n = 45. NOTES: Backwaters of the Colorado River and canals, floating aquatic in still or slow-moving water, occasionally stranded on mud: La Paz and Yuma cos. (Fig. 1); 20-100 m (60-300 ft); native of s Brazil, naturalized in regions with warm climates nearly SUBMERGED LEAVES: 1.5-6.0 cm long, short-petiolate, the root-like blade with numerous branches mostly near the base, with dense dark multicellular hairs. REFERENCES: Yatskievych, G. and M.D. Windham. 2008. Vascular Plants of Arizona: Salviniaceae. CANOTIA 4 (2): 46-49