3. Wolffiella (Hegelmaier) Hegelmaier, Botanische Jahrbucher fur Systematik, Pflanzengeschichte und Pflanzengeographie. 21: 303. 1895.
[For Johann Friedrich Wolff, 1778--1806, German physician, and Latin ella, diminutive]
Wolffia Horkel ex Schleiden subg. Wolffiella Hegelmaier, Lemnac., 131. 1868
Roots absent. Fronds submersed (except when flowering or fruiting), proximal part near surface, 1 or 2--20 or more, coherent, linear, ribbon-, sabre- or tongue-shaped, or ovate, flat, longer than 2 mm, margins entire; air spaces in tissue; pouch 1, terminal, at base from which daughter fronds (no flowers) originate, triangular, lower wall of pouch with tract of elongated cells forming connection between node and attachment to mother frond; veins 0; scale at base of frond absent; anthocyanins absent; pigment cells present (visible in dead fronds as brown dots); turions absent. Flowers 1(--2) per frond, originating in cavity at side of median line of upper frond surface, not surrounded by utricular scale; stamen 1, 2-locular. Seeds 1, nearly smooth. x = 10, 20, 21.
Species 10 (3 in the flora): North America, West Indies, Central America, South America, Africa.