Thallus thin, unsymmetrical, rootless, curved in the form of a segment of a band, punctate on both surfaces with numerous brown pigment-cells. Pouch opening as a cleft in the basal margin of the thallus, a stipe attached to its margins. Flowers and fruit unknown. [Diminutive of Wolffia.]

About 7 species, mostly of tropical regions. Besides the following, 2 others are known from western North America. Type species: Wolffiella oblonga (Phil.) Hegelm.

4 Wolffiella Hegelm Engler s Bot Jahrb 21 303 1895 1130

1. Wolffiella Floridana (J. D. Smith) Thompson. Florida Wolffiella

Fig. 1130

Wolffia gladiata var. floridana J. D. Smith, Bull. Torr. Club 7: 64.

1880. Wolffia floridana J. D. Smith; Hegelm. Engler's Bot. Jahrb. 21:

305. 1895.

Wolffiella floridana Thompson, Ann. Rep. Mo. Bot. Card. 9: 17-


Thalli solitary, or commonly coherent for several generations forming densely interwoven masses, strap-shaped, scythe-shaped, or doubly curved, tapering from the rounded oblique base to a long-attenuate apex, 21/2"-5" long, 14-21 times as long as wide; basal portion of the long stipe persistent, the pouch elongated-triangular, or the upper angle rounded.

Georgia and Florida to Missouri, Arkansas and Texas.