Riccia subplana Steph.

Riccia subplana Stephani, Symb. Ant. 3: 275. 1902
Riccia guadalupensis Stephani, in herb.
Thalli medium-sized, 4-15 mm. long, forming rosettes or irregularly gregarious, 2 or 3 times furcate, regularly reticulate and whitish-green above (when dry), concolorous below or more or less tinged with violet-purple at and near the margins; main segments oblong or oblong-obovate, 1.5-3.5 mm. wide; terminal segments similar, rounded-obtuse, emarginate; margins acute or submembranous, ascending; median sulcus rather acute and well defined in anterior parts; scales small, mostly 2-4 cells broad, widely spaced, now and then slightly exceeding the margins, commonly violet-purple; transverse sections of the thallus arcuatesemiorbicular to arcuate-subfusiform, 2-6 times as broad as high, 15-20 cells thick in median parts; dorsal epidermis 2-stratose, the cells of the primary stratum hemispheric or domeshaped, soon collapsing and leaving inconspicuous vestiges, the cells of the succeeding stratum mostly 40-75 m broad, in rather distinct and regular rows when viewed from above. Monoicous; antheridial ostioles elevated 75-160 fi; capsules usually long included; spores at first tinged with violet, soon violet-brown, 80-117 m in maximum diameter, subspheric or ellipsoid, destitute of wing-margins, almost uniformly areolate-alveolate over the whole surface, the areolae mostly 10-20 /i broad, remaining distinct, the angles of the lamellae commonly developing obtuse or tnmcate trabeculae 6-13 ju high.
Type locality : Martinique. Distribution: Guadeloupe and Martinique.