Asterella tenella (L.) P. Beauv.

Asterella tenella (L.) Beauv. Diet. Sci. Nat. 3: 257, 1805
Marchantia tenella L. Sp. PI. 1137. 1753.
Fimbriaria tenella Nees, Horae Phys. Berol. 45. 1820.
Fimbriaria nigripes Bisch.; Lehm. Stirp. Pug. 6: 19. 1834.
Fimbriaria tenella porphyrocephala Bisch. Nova Acta Acad. Leop. -Carol. 17: 1023. 1835
Fimbriaria tenella brcSthypus G. L. N. Syn. Hep. 563. 1846.
Fimbriaria brachypus Mont.; G. I.. N. Syn. Hep. 563, as synonym. 1846.
Fimbriaria mollis Tayl. Lond. Jour. Bot. 5: 411. 1846.
Hypenantron tenellum Trevisan, Mem. 1st. Lomb. 13: 440. 1877.
Hypenantron molle Trevisan, Mem, 1st. X-omb. 13: 441. 1877, Thallus bright-green, often pigmented with purple beneath and along the margin, mostly 0.5-1.5 cm. long and 1.5-3mm. wide, with a rounded keel and thin undulate margins, branching almost invariably by forking; epidermal cells averaging about 40 X 25 m with slightly thickened walls, the trigones sometimes distinct; cells containing oil-bodies few and scattered ; pores slightly or not at all elevated, surrounded by about 6 radiating series of cells with 2 or 3 cells in each series, the radial walls thin; green tissue loose, the air-chambers not subdivided, each dorsal chamber with a. pore; appendages of ventral scales one or two, narrowly to broadly ovate, mostly 0.25-0.45 mm. long and 0.15-0.3 mm. wide, acute to rounded, the margin entire or somewhat dentate. Paroicous; antheridia forming a small group anterior to the female receptacle; stalk of female receptacle naked, often purple, about 2 cm. long, the disc 2-4 mm. wide, hemispheric, smooth or nearly so, shortly lobed, the lobes mostly 4, extending obliquely downward; involucre deeply bifid, entire or irregularly sinuate or crenate; pseudoperianth mostly 8-10-cleft, white or yellowish or purplish, the segments finally free, ovate to lanceolate; operculum remaining intact at dehiscence; spores yellow, mostly 80-90 ix in diameter with wavy wings 8-15 ju wide; spore-surfaces covered with fine and irregular lines and also with coarse ridges, forming a reticulum on the spheric face with meshes 16-18 fi wide ; elaters yellow, mostly 10-12 m wide, bispiral in the middle and unispiral at the ends.
Type locality: Virginia.
Distribution: Maine to Ontario, and southward to Georgia, I^ouisiana, and Texas; on banks