Part 224 (1/2)

Thallus large, forking, areolate, porose, with broad diffused midrib; gemmae in a cup-shaped receptacle. Dicious. Fertile receptacle peduncled from an apical sinus of the thallus, radiately lobed. Involucres alternate with the rays, membranous, lacerate, enclosing 3--6 1-fruited cleft perianths. Calyptra persistent. Capsule globose, exserted, pendulous, dehiscing by several revolute segments. Elaters long, attenuate to each end. Spores smooth. Antheridia immersed in a peduncled disk-like radiate or lobed receptacle. (Named for _Nicholas Marchant_, a French botanist.)

1. M. polymorpha, L. Thallus 2--5' long, --1' wide, numerously porose, venulose; receptacle divided into usually 9 terete rays; peduncles 1--3'

high; antheridial disk crenately or palmately 2--8-lobed, on a peduncle 1' high or less.--Everywhere common. (Eu.)

2. PRESSIA, Nees. (Pl. 22.)

Thallus obcordate, sparingly forked, increasing by joints; pores conspicuous; gemmae none. Dicious or moncious. Fertile receptacle hemispheric, 1--4-lobed, with as many alternating shorter rib-like rays.

Outer involucres attached beneath the lobes, 1--3-fruited, opening outward by an irregular line; perianth obconic-campanulate, angular, unequally 4--5-lobed. Calyptra persistent. Capsule large, distinctly pedicelled, dehiscing by 4--8 revolute segments. Elaters short. Spores coa.r.s.ely tuberculate. (Named for _L. Preiss_, a German botanist.)

1. P. commutata, Nees. Thallus 1--2' long, with conspicuous white pores above, and dark purple scales beneath; usually moncious; peduncle --1'

high; capsules conspicuous, dark purple; antheridia in a peduncled disk-like receptacle. (P. hemisphaerica, _Cogn._)--On slaty and limestone rocks, from N. J. north and westward. (Eu.)

3. FIMBRIaRIA, Nees. (Pl. 22.)

Thallus thickened in the middle by a keeled costa, usually conspicuously porose, with dark purple scales beneath; gemmae none. Moncious.

Receptacle rising from the apex, conic or hemispheric, concave beneath and expanded into usually 4 large campanulate 1-fruited involucres.

Perianth oblong-oval or subconic, exserted half its length and cleft into 8--16 fringe-like segments. Calyptra with a long style, fugacious.

Capsule nearly sessile, irregularly circ.u.mscissile. Elaters rather short, 1--4-spiral. Spores angular, subreticulated. Antheridia immersed in the thallus. (Name from _fimbria_, a fringe, alluding to the perianth.)

1. F. tenella, Nees. Thallus of one or more long-wedge-shaped emarginate divisions about 6--9” long, grayish-green and porose above, purple on the margins; peduncle 1' high or more, usually purple; receptacle obtusely conic; perianth white, 8-cleft.--On damp ground in sandy fields or on rocks, central N. Y. to Mo., and southward.

4. CONOCePHALUS, Neck. (Pl. 22.)

Thallus dichotomous, copiously reticulate and porose, with a narrow costa; gemmae none. Receptacle conic-mitriform, membranous. Involucres 5--8, tubular, 1-fruited, suspended from the apex of the peduncle; perianth none. Calyptra persistent, campanulate, 2--4-lobed at the apex.

Capsule pedicelled, oblong-pyriform, dehiscing by 5--8 revolute segments. Elaters short, thick. Spores muriculate. Antheridia imbedded in an oval disk sessile near the apex of the thallus. (Name from ?????, _a cone_, and ?efa??, _a head_.)

1. C. conicus, Dumort. Thallus 2--6' long, --' wide; receptacle conic, striate, crenate. (Fegatella conica, _Corda._)--Shady banks; common.

(Eu.)

5. GRIMaLDIA, Raddi. (Pl. 23.)

Thallus thick, more or less channelled, dichotomous, innovating from the apex, with thick epidermis, closely areolate and porose-scabrous above, purple and more or less scaly beneath; gemmae none. Moncious or dicious. Receptacle peduncled, hemispherical or conoidal, 3--4-lobed.

Involucres as many, 1-fruited, each a distention of the lobe. Capsule filling the involucre, circ.u.mscissile in the middle, the calyptra persistent at its base. Antheridia in an oval or obcordate disk immersed in the apex of the thallus. (Named for _D. Grimaldi_, an Italian botanist.)

1. G. barbifrons, Bisch. (Pl. 23.) Thallus linear-obcuneate, 3--6”

long, 1--2” wide, 2-lobed at the apex, pale green with usually distinct whitish pores, the scales beneath often extending far beyond the margin and becoming whitish; peduncle profusely chaffy at base and apex, sometimes much reduced; antheridial disks obcordate. (Including G.

sessilis, _Sulliv._)--Thin soil on rocks, Conn. and N. J. to Iowa; rare or local. (Eu.)

2. G. rupestris, Lindenb. Thallus 3--6” long, 1--3” wide, with membranous margins; receptacle small, hemispherical, 1--4-fruited, the peduncle about 1' high, sparingly scaly at base, barbulate at the apex; involucre short, crenulate; spores tuberculate. (Duvalia rupestris, _Nees_.)--On calcareous or shaly rocks, N. Y. and Ohio. (Eu.)

6. ASTEReLLA, Beauv. (Pl. 22.)

Thallus rigid, very indistinctly porose, the midrib broad, strong and distinct. Receptacle conic-hemispheric, becoming flattened, 1--6- (usually 4-) lobed. Moncious. Involucres coherent with the lobes, 1-fruited, 2-valved. Calyptra minute, lacerate, persistent at the base of the capsule. Capsule greenish, rupturing by irregular narrow teeth or by a fragmentary operculum. Elaters moderately long, mostly 2-spiral.