276 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
5. Asterella saccata (Wahl.) Evans, 
Marchantia fragrans Schleich. Pl. Crypt. Exsic. Helvet. 3: 64. 1804, nomen 
nudum; Lam. & DC. Fl. Frane. ed. 3. 2: 423. 1805, not Balb. 
Marchantia saccata Wahl. Ges. Naturf. Freund. Berlin Mag. 5:-296. pl. 7, 
7. 8 1811. 
Fimbriaria saccata Nees, Hor. Phys. Berol. 45. 1820. 
Fimbriaria fragrans Nees, loc. cit. 
Hypenantron ciliatum Corda; Opiz, Beitr. Naturg. 648. 1828, nomen nudum. 
Marchantia umbonata Wallr. Linnaea 14: 686. 1840. 
Fimbriaria umbonata Wallr.; Gottsch., Lind. & Nees, Sy. Hep, 559. 1846. 
Asterella fragrans Trevis, Rend. Ist. Lombardo II, 7: 785. 1874. 
Hypenantron fragrans Trevis. Mem, Ist. Lombardo ITI. 4: 440. 1877. 
Hypenantron umbonatum Trevis. loc. cit. 
Hypenantron saccatum Trevis. loc, cit. 
Thallus green but more or less pigmented with purple on the ventral surface 
and along the margin, mostly 0.5 to 1 cm. long and 2 to 3 mm. wide, plane or 
somewhat concave when moist, the undulate margins strongly incurved when 
dry, branching by forking, the keel broadly rounded to bluntly carinate; epider- 
mis composed of cells with more or less thickened walls and distinct trigones, 
averaging about 30 X 20 »; pores more or less elevated, measuring (with their 
surrounding cells) mostly 70 ‘to 140 uw in length and 50 to 70 w in width sur- 
rounded by 6 (sometimes 5 or 7) series of cells with 2 or 3 cells in each series, 
the radial walls thin or with trigones; cells containing oil bodies as in A. te- 
nella; green tissue fairly loose, the air chambers in 2 or 83 layers (in the median 
portion), those of the dorsal layer larger than the others and more or less sub- 
divided by supplementary partitions (sometimes, not quite reaching the epider- 
mis), the chambers thus apparently more numerous than the pores; compact 
tissue occupying about two-thirds the thickness of the thallus in the median 
portion, thinning out gradually on the sides and extending about three-fourths 
the distance to the margin, composed of cells with thin unpitted walls; mycor- 
hiza not observed; ventral scales imbricated, deeply pigmented with purple 
except along the minutely and irregularly crenulate or denticulate margin, the 
cells containing oil bodies mostly 10 to 15, scattered, the appendages borne singly 
or in pairs, in the latter case sometimes more or less connate, subulate and long- 
acuminate, scarcely or not at all constricted at the base, mostly 0.7 to 1 mm. 
long and 0.2 to 0.3 mm. wide, hyaline, forming a conspicuous cluster at the tip 
of the thallus, the margin varying from entire to sparingly and irregularly dent- 
ate or spinose-dentate, the cells averaging about 55 X 20 u, not varying greatly in 
different parts, an occasional cell with oil bodies present in the basal portion ; 
inflorescence paroicous or autoicous, the antheridia forming an irregular elon- 
gated median group close to the peduncle of the female receptacle or on a sepa- 
rate branch; ostioles low; no paleae present; peduncle arising from the apex of 
a leading branch, surrounded at the base by a dense cluster of hyaline lanceolate 
scales, otherwise naked, more or less pigmented, about 2 cm. long when well 
developed; disk of receptacle bluntly conical, about 3 mm. wide, covered with 
coarse and low tubercles, shortly 3 or 4-lobed, the lobes extending almost verti- 
cally downward, the margins and distinct membranous involucre entire or more 
or less sinuate; pseudoperianth white, mostly 8-cleft, the lanceolate divisions 
coherent at the apex; capsule opening by an irregular circular line above the 
middle, the operculum coming off in one piece; spores brownish yellow, 80 to 
90 » in diameter, with wavy, minutely and irregularly crenulate wings 10 to 
12 » wide along the edges, the whole surface covered over with a very fine and 
