Palmer's Asterella

Asterella palmeri (Aust.) Underw. Bot. Gaz. 20: 63. 1895
Fimbriaria Palmeri Aust. Bull. Torrey Club 6: 47. 1875. Fimbriaria nudata M. A. Howe, Erythea 1: 112. 1893. Asterella nudata Underw. Bot. Gaz. 20: 61. 1895.
Thallus green above but more or less pigmented with purple beneathand along the margin, mostly 0.5-1 cm. long and 2-4 mm, wide, with a rounded keel and undulate, crispate, somewhat scarious margins becoming strongly incurved when dry, the branching dichotomous; epidermal cells averaging about 35 X 25 fi, thin-walled and without trigones; cells containing oil-bodies not present; pores elevated, surrounded usually by 6 radiating series of cells with 2 cells in each series, the cells next the opening with more or less thickened radial walls; green tissue compact, the air-chambers not subdivided, those of the dorsal layer vertically elongate, each with a pore ; compact ventral tissue composed of thin-walled cells without pits ; appendages of ventral scales one or (rarely) two, broadly to narrowly subulate, mostly 0.5-0.9 mm. long and 0.1-0.25 mm. wide, acuminate, the margin entire to sparingly dentate. Paroicous; antheridia forming a small group anterior to the female receptacle; stalk of female receptacle naked, more or less brownish, mostly 1-2 cm. long, the disc obtusely conic, about 4 mm. high and 2.5-4 mm. wide, smooth or nearly so, scarcely lobed; involucre entire or nearly so, narrow; pseudoperianths mostly three or four, extending vertically downward, white, 8~12-cleft, the segments connate at their tips, lanceolate; operculum remaining intact at dehiscence; spores dark-brown to almost black, 60-80 m in diameter, with low wavy folds about 5 ju wide along the edges and with similar folds on the spore-faces, the latter folds (sometimes reduced to tubercles) crowded and interwoven but not forming a network; spore-surface otherwise smooth or obsciurely punctulate; elaters pale-brown to dark-brown, mostly 12-14 ju in diameter, sometimes unispiral throughout but usually bispiral in the middle.
Type locality: Guadalupe Island, Lower California. Distribution: California and Lower California.