1. M. Taylòri, S. F. Gray. Stems erect, nearly simple, radiculose; leaves large, convex, orbicular, entire, purplish; cells large; underleaves lance-subulate, entire or subdentate; perianth terminal, oval; calyptra finally long-exserted. (Jungermannia Taylori, Hook.)—Wet rocks, high mountains of N. Eng. and N. Y. (Eu.)

22. HARPÁNTHUS, Nees. (Pl. 23.)

Leaves succubous, semi-vertical, ovate, emarginate; underleaves connate with the leaves, ovate or lanceolate, 1-toothed at base. Diœcious. Fruit on short shoots from the axils of the underleaves, finally sublateral. Involucral leaves 2 or 4. Perianth terete, the lower half thickened. Calyptra fleshy, confluent with the perianth for {2/3} its length. Capsule oval. Antheridia 1 or 2 in the axils of bracts terminal on slender branches. (Name from ἅρπη a sickle, and ἄνθος, flower.)

H. Flotoviànus, Nees. (Pl. 23.) Stems flexuous, procumbent, mostly unbranched; leaves ovate-orbicular, horizontal, the apex contracted and emarginate with a shallow sinus; underleaves large, ovate or lanceolate, obliquely inserted, entire or more often toothed on one or both sides near the middle; diœcious; perianth subcylindric, slightly sickle-shaped, the mouth pointed at first, notched on one side and finally crenulate; antheridia elliptic, single in the base of swollen leaves. (Pleuranthe olivacea, Tayl.)—"North America" (Drummond), but not collected recently; certainly extralimital.

23. LIOCHLÆ̀NA, Nees. (Pl. 25.)

Leaves succubous, ovate-oblong, entire or slightly retuse; underleaves none. Diœcious or monœcious. Involucral leaves 2 or 4, like the cauline; perianth pyriform, becoming cylindric, incurved, abruptly rounded at the summit, the minute orifice prominently ciliolate. Capsule oblong, long-exserted. Elaters attached to the middle of the valves. Spores minute, globose. Antheridia in the axils of ordinary leaves. Archegonia 5–12. (Name from ληῖος, smooth, and χλαῖνα, a cloak, referring to the perianth.)

1. L. lanceolàta, Nees. Closely creeping, branched; leaves sometimes decurrent; involucral leaves vertical; perianth at right angles with the stem; monœcious.—On banks and rotten logs; not rare. (Eu.)

24. JUNGERMÁNNIA, Micheli. (Pl. 25.)

Leaves succubous, rarely subtransverse, entire, lobed or dentate, the margins never recurved; underleaves present or none. Diœcious or monœcious. Fruit terminal. Involucral leaves 4 or fewer, like the cauline or more incised, free; perianth laterally compressed or terete, usually 3–10-carinate, the usually small mouth entire or toothed. Calyptra oval-pyriform. Capsule globose or oblong, rarely cylindric. Spores minute, smooth or roughish. Archegonia 8–70. (Named for L. Jungermann, a German botanist of the 17th century.)

§ 1. JUNGERMANNIA proper. Leaves orbicular or ovate, entire or barely retuse; underleaves none (very small in n. 1).

1. J. Schràderi, Martius. (Pl. 25.) Creeping, flexuous; leaves round-elliptic, entire, ascending; underleaves broadly subulate, not apparent on old stems; involucral leaves large, elongated, the inner smaller and more or less laciniate; perianth oval-obovate, ascending.—On the ground and rotten logs; common. (Eu.)

2. J. sphærocárpa, Hook. Stems creeping, the tips ascending, subsimple, greenish; leaves semi-vertical, rather rigid, orbicular, obliquely spreading, decurrent dorsally, pale green; involucral leaves separate; perianth exserted, obovate-oblong, the mouth 4-cleft; capsule globose.—Mountains of N. Eng. (Austin); rare. (Eu.)

6. J. barbàta, Schreb. (Pl. 25.) Procumbent, sparingly branched; leaves roundish-quadrate, with obtuse, acute, or mucronulate lobes and obtuse undulate sinuses; underleaves broad, entire or 2-toothed, sometimes obsolete; perianth ovate, plicate-angled toward the apex, denticulate.—On rocks in mountain regions; common. (Eu.)

Var. attenuàta, Martius. Ascending, with numerous offshoots; stem-leaves semi-vertical, obliquely spreading, roundish, acutely 2–4-toothed, those of the shoots closely imbricate, premorsely 2–4-denticulate; involucral leaves two, 3-toothed; perianth oblong.—In similar localities. (Eu.)

7. J. setifórmis, Ehrh. Erect or ascending, dichotomous; leaves toothed at base, 3–4-cleft, the lobes ovate-oblong, acute, channelled; underleaves ciliate-dentate at base, deeply bifid, the divisions lanceolate, acuminate; involucral leaves more toothed than the cauline; perianth terminal, oval, plicate.—Alpine summits of N. H. (Oakes). (Eu.)

[*][*] Underleaves wanting.

[+] Leaves 2-toothed; involucral leaves 2–4-cleft.

8. J. alpéstris, Schleich. Stems creeping, crowded, bifid-branching, the ends ascending; leaves semi-vertical, ovate subquadrate, obliquely toothed, the teeth unequal, acute or mucronulate, distant; involucral leaves wider, 2–3-cleft; perianth twice as long, oblong, smooth, the mouth complicate; capsule oval.—Alpine region of N. H. (Oakes). (Eu.)

9. J. ventricòsa, Dicks. Stems dense, close-creeping, branching from beneath; leaves semi-vertical, subquadrate, mostly flat, broadly and acutely emarginate-bidentate, often bearing globules; involucral leaves larger, round, erect-spreading, 3–4-cleft, subdentate; perianth ovate, inflated, narrowly complicate above; capsule oval.—On the ground and rotten wood in the mountains, and far northward; common. (Eu.)

16. J. Helleriàna, Nees. (Pl. 25.) Creeping, entangled; leaves spreading, subascending, cleft {1/3}–½ their length, the lobes equal, acute, entire or serrate; involucral leaves 2–3-cleft, spinulose serrate; perianth ovate, the mouth contracted.—On rotten wood, N. Y., N. Eng., and northward. (Eu.)

§ 4. GYMNOCÓLEA. Leaves 2-lobed; underleaves none; involucral leaves like the cauline; perianth pedunculate, denticulate.

17. J. inflàta, Huds. (Pl. 25.) Procumbent or ascending, loosely radiculose, branching; leaves semi-vertical, roundish-elliptic, inequilateral, the sinus and unequal lobes obtuse; perianth terminal or at length dorsal, oval or pyriform, smooth, the mouth connivent; capsule oblong.—On sterile ground and rocks, N. J. (Austin), and northward in the mountains. (Eu.)

25. MARSUPÉLLA, Dumort. (Pl. 23.)

Stems dorsally compressed, with rootlets at the base and often producing somewhat leafless runners. Leaves transverse, complicate-bilobed; involucral leaves 2 or 4, connate with the perianth. Perianth tubular or oval, subcompressed parallel to the base of the leaves. Elaters free. Spores round, rufous (in our species). Antheridia mostly terminal. (Name a diminutive of marsupium, a pouch, from the form of the perianth.)

1. M. sphacelàta, Dumort. Stems erect, subflexuous, pale brown; leaves rather distant, concave, obovate to obcordate, somewhat clasping, the sinus narrow; diœcious; involucral leaves larger than the cauline, cordate; perianth free at the apex, with 4–5 broad acute teeth; antheridia 1–3, in short terminal spikes.—Wet rocks, mountains of N. Eng. to N. J., and southward. (Eu.)

2. M. emarginàta, Dumort. (Pl. 23.) Stems simple or innovating at the summit, rigid, somewhat thickened upward; leaves usually broader than long, round-cordate or subquadrate, lobes obtuse or mucronate, sinus acute; diœcious; involucral leaves 4–8, usually larger, more deeply and acutely emarginate; perianth urceolate, the closed apex splitting into 4–5 triangular lobes; antheridia 2–3, oval, axillary in terminal spikes. (Sarcoscyphus Ehrharti, Corda.)—On wet rocks, chiefly in mountain rivulets, N. Y. and N. Eng. Floating forms are longer with distant leaves. (Eu.)

3. M. adústa, Spruce. Stems minute, clavate; leaves (5–8 pairs) imbricate, round or broadly ovate from a sheathing base, acutely lobed with angular sinus; monœcious; perianth included, campanulate, crenate becoming irregularly lobed; spores punctate; antheridia 1 or 2, oval, in the axils of the lower involucral leaves. (Gymnomitrium adustum, Nees.)—Alpine region of the White Mts. (Oakes, Austin). (Eu.)

26. NÁRDIA, S. F. Gray. (Pl. 25)

Stems laterally compressed, usually without runners. Leaves succubous, subconcave or flat, the apex rounded, rarely retuse or bidentate; underleaves none (in our species). Monœcious or diœcious. Involucral leaves 2–4 pairs, connate at base. Perianth subcompressed laterally, connate with the involucral leaves. Antheridia terminal on somewhat spike-like stems. (Named for S. Nardi, an Italian abbot.)

§ 1. EÙCALYX. Perianth connate at base with the inner involucral leaves, somewhat surpassing them, 3–8-carinate, the mouth constricted.

2. N. crenulàta, Lindb. (Pl. 25.) Prostrate, branching; leaves orbicular, entire, larger toward the involucre and with large marginal cells; diœcious; involucral leaves 2, rarely 3, adnate to the base of the perianth, which is flattened or terete, more or less regularly 4–5-plicate, the angles smooth; mouth much contracted, toothed. (Jungermannia crenulata, Smith.)—On the ground in old fields, N. Y. and southward. (Eu.)

3. N. crenulifórmis, Lindb. Densely cespitose; fertile stems creeping, thickened upward, with numerous purple rootlets, the sterile subascending, attenuate upward; leaves subdecurrent, obliquely spreading, orbicular, concave, entire or nearly so; perianth small, subobovate, more or less connate with the involucral leaves, not exserted or slightly so, rooting at base, triquetrous above, becoming 4–7-plicate; calyptra often violet-purple; capsule oval-globose. (Jungermannia crenuliformis, Aust.)—On rocks in rivulets, Closter, N. J. (Austin), Coshocton Co., Ohio (Sullivant).

4. N. bifórmis, Lindb. Densely cespitose, much branched, innovating from beneath; rootlets numerous; leaves scarcely imbricate, alternate, spreading, obliquely semicircular or broadly ovate, retuse or entire, decurrent dorsally; cells large, hyaline; branch-leaves half as large, ovate or obovate, scarcely decurrent; diœcious; antheridia solitary; fruit unknown. (Jungermannia biformis, Aust.)—On steep wet rocks, Delaware Water Gap, N. J. (Austin).

§ 2. CHASCÓSTOMA. Perianth exserted, subcampanulate and open, deeply laciniate, connate with the involucral leaves.

5. N. fossombronioìdes, Lindb. Stems densely cespitose, ascending; rootlets numerous, purple; leaves 2-ranked, subvertical, spreading-subrecurved, rooting, closely imbricate, orbicular, clasping by a slightly cordate base, subventricose, undulate-repand, the apex uniplicate and slightly emarginate; monœcious; perianth very large, 6–10-plicate, the lobes entire; calyptra violet; capsule short-oval. (Jungermannia fossombronioides, Aust.)—On rocks in a rivulet, Closter, N. J. (Austin), and southward.

27. GYMNOMÍTRIUM, Corda. (Pl. 23.)

Leaves closely imbricated, 2-ranked on fascicled ascending julaceous stems, emarginate-bidentate; underleaves none. Diœcious. Involucre double, the inner shorter, of 2 or more dentate and deeply cleft leaves. Calyptra short, campanulate. Capsule globose, the valves at length reflexed. Elaters caducous. Antheridia in the axils of leaves, oval, stipitate. (Name from γυμνός, naked, and μιτρίον, a little cap.)

1. G. concinnàtum, Corda. Stems simple or imbricately branching, thickened at the apex; leaves ovate, bifid, with a narrow scarious margin. (Cesia concinnata, S. F. Gray.)—Alpine regions of the White Mts. (Oakes).—Grayish or silvery-olive. (Eu.)

28. FOSSOMBRÒNIA, Raddi. (Pl. 23.)

Stems thalloid, with large subquadrate succubous leaves; underleaves none. Diœcious or monœcious. Fruit terminal or by innovation dorsal on the main stem. Involucral leaves 5–6 (in our species), small, subulate, adnate. Perianth open-campanulate or obpyramidal, crenate-lobed. Calyptra free, sub-globose. Capsule short-pedicelled, globose, irregularly valved. Elaters very short, 1–3- (mostly 2-) spiral, free. Spores large, very rough. Antheridia 2–3, short-pedicelled, naked. Perfect archegonia 2–3. (Named for V. Fossombroni, an Italian Minister of State.)

[*] Plant large or of medium size; stems mostly simple.

1. F. pusílla, Dumort. (Pl. 23.) Stems 6–10´´ long; leaves retuse, entire or irregularly indented; perianth obconic, dentate; elaters short and thick; spores brown, depressed-globose-tetrahedral, 40 µ broad, crested, the slender crests pellucid, rarely becoming confluent.—On damp ground. Its occurrence in America is doubtful. (Eu.)

2. F. Dumortièri, Lindb. Cespitose, greenish or brownish-yellow; stems 3–6´´ long, 1´´ wide, shortly bifurcate; rootlets copious, purple; leaves numerous, smaller toward each end of the stem; monœcious; perianth large, broadly obpyramidal; calyptra nearly as long; elaters scanty; spores globose-tetrahedral yellowish-brown, regularly pitted.—White Mts. (Farlow), N. J. (Austin), and perhaps elsewhere; confused with n. 1.

3. F. angulòsa, Raddi. Stems narrowly forked at the apex; leaves horizontal, subquadrate, the upper undulate-lobed; diœcious; perianth dilated-conic, crenate; spores brownish-yellow, globose-tetrahedral, not depressed, 30 µ broad, deeply reticulated, the reticulations large, 5–6-angled.—Brackish meadows, common; fruiting in early spring. (Eu.)

[*][*] Plant minute; stems forked or fastigiately divided.

4. F. crístula, Aust. Stems 1–2´´ long; leaves whitish, quadrate or round-obovate, subentire, strongly crisped-undulate; capsule immersed on a short pedicel; elaters short, more or less diverse, with a single narrow annular and spiral fibre; spores pale fuscous, more or less tuberculate.—On moist sand in unfrequented paths, Batsto, N. J. (Austin).

29. PALLAVICÍNIA, S. F. Gray. (Pl. 22.)

Thallus with a distinct costa. Fruit arising from the costa, at first terminal, becoming dorsal. Diœcious. Involucre cup-shaped, short-lacerate. Perianth long-tubular, denticulate. Calyptra irregularly lacerate. Capsule slender-cylindric. Elaters slender, free. Spores minute. Antheridia dorsal, covered with minute fimbriate scales. (Named for L. Pallavicini, Archbishop of Genoa.)

1. P. Lyéllii, S. F. Gray. Thallus thin, 1–4´ long, 3–5´´ wide, simple or bifid, the margin entire, slightly crenate or serrate; cells large, oblong-hexagonal; perianth erect, fleshy (5 cells thick below), the somewhat constricted mouth lobate-ciliolate; pedicel long, exceeding the thallus; capsule cylindric, five times as long as broad. (Steetzia Lyellii, Lehm.)—Among mosses in swamps and on dripping rocks; common, especially southward. (Eu.)

30. BLÀSIA, Micheli. (Pl. 23.)

Thallus simple or forked or stellate, with sinuous margins. Diœcious. Fruit from an oval cavity in the costa. Involucre mostly none. Calyptra obovate. Capsule oval-globose. Antheridia immersed in the thallus, covered with dentate scales. Gemmæ globose, issuing by a slender ascending tube from large flask-shaped receptacles which are immersed in the thallus. (Named for Blasius Biagi, a monk of Valombrosa and companion of Micheli.)

1. B. pusílla, L. Thallus ¾–1½´ long, 2–3´´ wide, narrowly obovate, the margins pinnatifid-sinuous.—Wet banks; common. (Eu.)

31. PÉLLIA, Raddi. (Pl. 23.)

Thallus with a broad indeterminate costa. Monœcious or diœcious. Fructification dorsal near the end of the thallus. Involucre short, cup-shaped, lacerate-dentate. Calyptra membranous, oval, longer or shorter than the involucre. Capsule globose. Elaters long, free. Antheridia globose, immersed in the costa. (Named for A. L. Pelli, an Italian botanist.)

[*] Monœcious.

1. P. epiphýlla, Raddi. (Pl. 23.) Thallus oblong, lobed and sinuate, somewhat fleshy, much thickened in the middle; capsule exserted.—On the ground in wet places; not uncommon eastward. (Eu.)

[*][*] Diœcious.

2. P. endiviæfòlia, Dumort. Thallus flat, green or purplish, broadly linear, dichotomous, the margin mostly undulate or crisped.—On the ground and in ditches; common, but often confused with n. 1. (Eu.)

3. P. calycìna, Nees. Thallus dichotomous, proliferous, the early divisions linear-oblong, the margins ascending and remotely sinuate, the later divisions linear-palmatifid, coarsely nerved; cells large, hexagonal; involucre ciliate-fringed or lacerate; calyptra smooth, included.—Wet limestones and shales. (Eu.)

32. METZGÈRIA, Raddi. (Pl. 23.)

Thallus linear, dichotomous, with well defined costa. Diœcious. Fructification arising from the under side of the costa. Involucre 1-leaved, scale-like, at length ventricose. Calyptra clavate or pyriform, fleshy. Capsule short-pedicelled. Elaters unispiral, some remaining attached to the tips of the valves. Spores minute, mostly smooth. Antheridia globose, enclosed in a scale on the under surface of the costa. (Named for J. Metzger, a German botanist.)

[*] Densely villous throughout.

1. M. pubéscens, Raddi. Thallus 1–2´ long, 1´´ wide, alternately pinnate or somewhat decompound, the short linear branches of uniform width, flat, the margin undulate; hairs longer beneath, single or in twos and threes near the margin, irregularly curved; midrib nearly without cortical layer, with 6–10 (mostly 8) rows of very uniform peripheral cells; diœcious.—In mountain regions, eastward. (Eu.)

[*][*] Hairy on the margins and midrib beneath, smooth above; diœcious (n. 4 monœcious).

33. ANEÙRA, Dumort. (Pl. 23.)

Thallus fleshy, prostrate or assurgent from a creeping base; costa obscure. Diœcious or monœcious. Fructification arising from the under side near the margin. Involucre cup-shaped, short and lacerate, or none. Calyptra large, fleshy, more or less clavate. Capsule large, oblong-cylindric. Elaters unispiral, in part adherent to the tips of the valves. Spores minute, smooth or minutely roughened. Antheridia immersed in the surface of receptacles proceeding from the margin of the thallus. (Name from α- privative, and νεῦρον, a nerve.)

[*] Thallus narrow (about 1´´ wide), palmately divided.

1. A. látifrons, Lindb. Thallus cespitose, ascending or erect, usually dark green, 6–9´´ long, mostly pellucid; branches linear, obtuse and emarginate, plano-convex; cells large, oblong-rhombic; monœcious; archegonia 3–10, short, conic; calyptra white, verrucose, pyriform-clavate; capsule oval, brown; spores 12½–14½ µ broad, globose, minutely and densely papillose; antheridia globose. (A. palmata of authors; not Dumort.)—On rotten logs; common.

[*][*] Thallus narrow (about 1´´ wide), pinnate or bipinnate.

2. A. multífida, Dumort. Thallus prostrate, brownish-green, pinnately divided, the primary portion biconvex, somewhat rigid, the branches horizontal, pectinately pinnate with narrow linear divisions; monœcious; fructification rising from the primary part or from the branches; involucre fleshy; calyptra tuberculate.—Var. màjor, Nees. Primary portion and branches thick, the branches interruptedly pinnate with short obtuse divisions.—On decayed wood and moss in swamps, N. J. (Austin), and south in the mountains. (Eu.)

3. A. pinnatífida, Nees. Thallus pinnately divided or subsimple, flat or somewhat channelled; branches horizontal, the broader pinnatifid or dentate, obtuse; calyptra somewhat smooth.—On dripping rocks, Hokokus, N. J. (Austin), N. Haven, Conn. (Eaton). (Eu.)

1. ANTHÓCEROS, Micheli. (Pl. 22.)

Thallus dark green or blackish, usually depressed, variously lobed, with large chlorophyll-grains, frequently glandular-thickened at the apex or in lines along the middle so as to appear nerved. Monœcious or diœcious. Capsule linear, 2-valved, exsertly pedicelled. Elaters simple or branched, often geniculate, more or less heteromorphous, the fibres wanting or indistinct. (Name from ἄνθος, flower, and κέρας, horn, from the shape of the capsule.)

1. A. læ̀vis, L. (Pl. 22.) Thallus smooth, nearly flat above; diœcious; involucre 1–2´´ long, trumpet-shaped when dry, repand-toothed; capsule pale brown or yellowish, 1–1½´ long; elaters rather short, yellowish; spores yellow, nearly smooth, angular.—Wet clay banks, from Canada south and westward. (Eu.)

2. A. punctàtus, L. Thallus small, depressed, or often cespitose and erect, more or less glandular; monœcious; involucre rather short, oblong-linear, slightly repand, sometimes scarious at the mouth; capsule 1´ high, black; elaters fuscous, flattish, geniculate; spores black, strongly muriculate, sharply angled.—Wet banks, Canada to Mo., and southward. (Eu.)

2. NOTOTHỲLAS, Sulliv. (Pl. 22.)

Thallus orbicular, tender, laciniate and undulate or crisped, papillose-reticulate. Monœcious. Involucre sessile, continuous with the thallus, opening irregularly above. Capsule very short, oblong-globose or ovate-cylindric, pedicelled from a thickened bulb, 2-valved to the middle or rupturing irregularly. Elaters none, or fragmentary and inconspicuous. Spores subglobose, smoothish. Antheridia elliptic-globose, immersed in the thallus. (Name from νῶτος, the back, and θυλάς, a bag, from the shape and position of the involucre.)

1. N. orbiculàris, Sulliv. (Pl. 22.) Thallus 3–8´´ wide; capsules 1–2´´ long, erect or decurved, wholly included or slightly exserted, of thin and loose texture, with a suture on each side; spores light yellowish-brown. (Including N. valvata, Sulliv.)—Wet places, Canada to the Gulf.

2. N. melanóspora, Sulliv. Thallus small, depressed or sometimes cespitose, of lax texture; capsule often without sutures; spores dark brown, a half larger.—Moist ground, Ohio (Sullivant).

Order 139. MARCHANTIÀCEÆ. Liverworts.

Plant-body a thallus, dichotomous or subpalmately branching, usually innovating from the apex or beneath it, more or less thickened in the middle, and bearing numerous rootlets beneath and usually colored or imbricating scales. Epidermis usually more or less distinct and strongly porose above. Capsules globose, rarely oval, opening irregularly, pendent from the under side of a peduncled disk-like receptacle (carpocephalum). Elaters present, mostly 2-spiral.

[*] Thallus plainly costate, distinctly porose except in n. 6.

[+] Gemmæ present on sterile stems.

1. Marchantia. Gemmæ in cup-shaped receptacles. Fertile receptacle 7–11-rayed.

8. Lunularia. Gemmæ in crescent-shaped receptacles. Fertile receptacle cruciform.

[+][+] Gemmæ wanting.

[++] Receptacle conic-hemispherical, 2–4-lobed; perianth lobed or fringed.

2. Preissia. Receptacle 2–4-lobed, with as many alternate rib-like rays. Perianth 4–5-lobed.

3. Fimbriaria. Receptacle 4-lobed. Perianth conspicuous, split into 8–16 fringe-like segments.

[++][++] Receptacle more or less conical; perianth none.

4. Conocephalus. Thallus very large, strongly areolate. Receptacle conical, membranous.

5. Grimaldia. Thallus small. Peduncle chaffy at base and apex. Receptacle conic-hemispheric, truncately 3–4-lobed.

6. Asterella. Thallus eporose. Receptacle conic-hemispheric, becoming flattened, acutely 4- (1–6-) lobed.

[*][*] Thallus thin, ecostate or barely costate.

7. Dumortiera. Receptacle convex, 2–8-lobed. Perianth none.

1. MARCHÁNTIA, Marchant f. (Pl. 22.)

Thallus large, forking, areolate, porose, with broad diffused midrib; gemmæ in a cup-shaped receptacle. Diœcious. 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.)

2. PREÌSSIA, Nees. (Pl. 22.)

Thallus obcordate, sparingly forked, increasing by joints; pores conspicuous; gemmæ none. Diœcious or monœcious. 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 coarsely tuberculate. (Named for L. Preiss, a German botanist.)

1. P. commutàta, Nees. Thallus 1–2´ long, with conspicuous white pores above, and dark purple scales beneath; usually monœcious; peduncle ½–1´ high; capsules conspicuous, dark purple; antheridia in a peduncled disk-like receptacle. (P. hemisphærica, Cogn.)—On slaty and limestone rocks, from N. J. north and westward. (Eu.)

3. FIMBRIÀRIA, Nees. (Pl. 22.)

Thallus thickened in the middle by a keeled costa, usually conspicuously porose, with dark purple scales beneath; gemmæ none. Monœcious. 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 circumscissile. 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. tenélla, 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. CONOCÉPHALUS, Neck. (Pl. 22.)

Thallus dichotomous, copiously reticulate and porose, with a narrow costa; gemmæ 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 κῶνος, a cone, and κεφαλή, a head.)

1. C. cónicus, Dumort. Thallus 2–6´ long, ½–¾´ wide; receptacle conic, striate, crenate. (Fegatella conica, Corda.)—Shady banks; common. (Eu.)

5. GRIMÁLDIA, 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; gemmæ none. Monœcious or diœcious. Receptacle peduncled, hemispherical or conoidal, 3–4-lobed. Involucres as many, 1-fruited, each a distention of the lobe. Capsule filling the involucre, circumscissile 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. bárbifrons, 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. rupéstris, 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. ASTERÉLLA, Beauv. (Pl. 22.)

Thallus rigid, very indistinctly porose, the midrib broad, strong and distinct. Receptacle conic-hemispheric, becoming flattened, 1–6- (usually 4-) lobed. Monœcious. 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. Spores tuberculate. Antheridia in sessile lunate disks. (Diminutive of aster, a star, from the form of the receptacle.)

1. A. hemisphæ̀rica, Beauv. Thallus forking and increasing by joints, pale green, purple beneath; receptacle papillose on the summit (less so at maturity); peduncle bearded at base and apex, ¾–1´ long, often 2–3 times longer after maturity. (Reboulia hemisphærica, Raddi.)—Shaded banks, chiefly along streams; more common southward.—A smaller form or perhaps variety (Reboulia microcephala, Nees; R. Sullivantii, Lehm.) occurs in Penn., Ohio, and southward. (Eu.)

7. DUMORTIÈRA, Nees. (Pl. 22.)

Thallus large, thin, soft, with a slight costa, dichotomous, usually with scattered hair-like rootlets beneath; gemmæ none. Receptacle convex, 2–8-lobed. Involucres 1-fruited, connate with the lobes beneath, horizontal, opening by a vertical terminal slit. Capsule distinctly pedicelled, oblong-globose, dehiscing by 4–6 irregular valves. Elaters 2–3-spiral, parietal, very long, straight, attenuate both ways. Spores muriculate. Antheridia in a short peduncled disk paleaceous beneath. (Named for B. C. Dumortier, a Belgian botanist.)

1. D. hirsùta, Nees. Thallus 2–5´ long, 6–9´´ wide, deep green, becoming blackish, entire on the margins, naked above or with a delicate appressed pubescence; diœcious; receptacle many-fruited, the margin closely hairy; peduncle rather long, chaffy at the apex.—On moist calcareous rocks, Easton, Penn. (Porter), and southward.

8. LUNULÀRIA, Micheli. (Pl. 25.)

Thallus oblong with rounded lobes, distinctly areolate and porose, with imbricate sublunate scales beneath; gemmæ in crescent-shaped receptacles. Diœcious. Fertile receptacle usually cruciately divided into 4 horizontal segments or involucres, which are tubular, vertically bilabiate and 1-fruited. Calyptra included, persistent. Capsule exserted, 4–8-valved. Elaters short, very slender, mostly free. Spores nearly smooth. Antheridia borne in the apical sinus of the thallus. (Name from lunula, a little moon.)

L. vulgàris, Raddi. Thallus 1–2´ long, forked, innovating from the apex, with a somewhat diffuse costa; peduncle very hairy, 1–1½´ long.—Introduced into greenhouses; always sterile, but easily recognized by the characteristic receptacles. (L. cruciata, Dumort.) (Int. from Eu.)

Order 140. RICCIÀCEÆ.

Plant-body a dichotomously branching thallus, terrestrial or aquatic. Capsules short-pedicelled, or sessile on the thallus, or immersed in its substance, free or connate with the calyptra, globose, at length rupturing irregularly. Calyptra crowned with a more or less deciduous point. Elaters none. Spores usually angular, reticulate or muriculate. Antheridia ovate, immersed in the thallus in flask-shaped cavities with protruding orifices (ostioles).

1. Riccia. Capsule immersed in the thallus. Involucre none.

2. Sphærocarpus. Capsule sessile on the thallus. Involucre inflated-pyriform.

1. RÍCCIA, Micheli. (Pl. 22.)

Thallus at first radiately divided, the centre often soon decaying; the divisions bifid or di–tri-chotomous, flat or depressed or channelled above, usually convex and naked or squamulose beneath; margins naked or spinulose-ciliate; epidermis usually distinct, eporose; air-cavities evident or wanting. Capsule immersed, sessile. Calyptra with a persistent style. Spores alveolate or muriculate, usually flattened and angular. (Named for P. F. Ricci, an Italian nobleman, patron of Micheli.)

§ 1. LICHENÒDES. Fruit mostly protuberant above; spores about 84 µ broad, issuing through openings in the upper surface of the thallus; terrestrial species (on damp, usually trodden or cultivated ground), without air-cavities.

[*] Thallus naked, without cilia or scales.

1. R. Fróstii, Aust. Thallus orbicular, 6–12´´ broad, thinnish, grayish-green, the apex and narrowly membranous margins sometimes purplish, minutely pitted; divisions linear or subspatulate, subtruncate and slightly emarginate; rootlets smooth or obsoletely papillose within; capsules very prominent beneath; spores barely 50 µ broad, nearly round, somewhat margined, with depressed sides when dry, fuscous.—Ohio, Ill., and westward.

[*][*] Thallus with white scales beneath (dark purple in n. 4), the margin naked.

8. R. lutéscens, Schwein. Orbicular, 1–1½´ in diameter, light green; divisions 6–8, linear, 2–3 times forked, narrowly channelled, obcordate and thickened at the apex, with delicate whitish obliquely ovate appressed scales, rootlets wanting beneath above the middle; fruiting plant unknown.—Dried up pools and ditches, Canada to Mo., and southward. An analogous form has been developed by Lindberg from R. natans.

11. R. nàtans, L. (Pl. 22.) Divisions obcordate or cuneate, broadly emarginate, 3–6´´ long, purplish, very narrowly channelled, with numerous uniform air-cavities beneath the epidermis, rooting toward the base and at length with dark purple scales beneath the apex; capsules in 1 or 2 rows beneath the groove; spores black, angular, strongly papillose.—Canada to the Gulf. (Eu.)

2. SPHÆROCÁRPUS, Micheli. (Pl. 22.)

Thallus lobed, without costa or epidermis. Involucres sessile, obconic or pyriform, perforated at the apex, continuous with the thallus at base. Calyptra closely investing the single globose indehiscent capsule, crowned with a deciduous point. Spores globose, muriculate, remaining united in a coccus. Antheridia borne in follicular bodies on the surface of a separate thallus.—An anomalous genus, perhaps more closely related to the Jungermanniaceæ. (Name from σφαῖρος, a sphere, and καρπός, fruit.)

1. S. terréstris, Smith. Thallus orbicular, 3–6´´ broad, covered by the clustered inflated involucres, which are nearly 1´´ long, 3–4 times the length of the capsule; coccus 102–127 µ wide, indistinctly lobed. (S. Michelii, Bellardi.)—In cultivated fields, mostly southern. (Eu.)