var. ß. Wahlenbergii; leaves flexuose and spreading, sheathing at the base, much attenuated above, narrower and longer, much contorted when dry, yellowish; capsule short, with a very prominent struma. Oncophorus Wahlenbergii Bridel, Bryol. Univ. i. 400. Dicranum virens Wahlenb. Fl. Lapp. p. 338. (ex parte). D. Richardsoni Hook. in Drummond, Musc. Amer. No. 106. Angstroemia Wahlenbergii C. Müller, Syn. Musc. ii. 610. var. y. serratum; loosely tufted; stems taller, sparingly branched; leaves recurved, or spreading and flexuous from a sheathing base, crisped when dry, coarsely serrated. var. d. compactum; densely tufted; stem shorter, more slender; leaves shorter, lanceolate from an ovate base, entire or scarcely toothed at the apex, lower ones lurid; capsule on a shorter pedicel, gibbous. D. Homanni Boeck. in Hartm. Skandinav. Flor. ed. 4. p. 384. var. ε. gracilescens, with narrower leaves and smaller capsules. D. microcarpum Hook. in Drummond. Musc. Am. No. 105. "strongly resembles D. virens var. compactum of Funk." (See remarks of Bruch and Schimper in Lond. Journ. Bot. Dec. 1843.) The var. 3. appears to us a distinct species belonging to the section Crispa, having the leaves suddenly dilated and sheathing at the base, the upper part much longer and more attenuated than in D. virens, distinctly serrulate above, margin not reflexed, the nerve thicker and much more prominent at the back. Var. . may indeed be only a slender compact state of D. virens, but the specimens collected in North America by Drummond with the leaves more suddenly dilated and sheathing below, the capsules furrowed when dry and empty, and the walls of thinner texture than in the typical form, belong to a probably different species, as given in the Synopsis of C. Müller. SECT. III. SQUARROSA. 3. Dicranum pellucidum Hedw. (transparent Fork-Moss); dioicous; stems loosely tufted; leaves squarrose, variously bent, lanceolate from a slightly sheathing base, rather obtuse, entire, serrated or crenulate at the apex, papillose on both sides; capsule ovate, subcernuous; lid rostrate. (TAB. XVII.) D. pellucidum Hedw. Sp. M. Schwaegr. Suppl. t. 48. Web. and Mohr. Swartz. Turner. Smith, Eng. Bot. t. 1346. Röhl. Bridel. Hook. and Tayl. Br. and Sch. Monogr. p. 16. t. 4, 4*. Bryum pellucidum Linn. Dill. Musc. t. 46. f. 23. Angstroemia pellucida C. Müller, Syn. Musc. ii. 606. var. B. fagimontanum; stem short, with slender branches; leaves shorter. Hook. var. y. serratum; leaves crenato-serrate; capsule oval, or oblong, erect, or suboblique; lid with a slender beak. D. flavescens Eng. Bot. t. 2263. Smith, Fl. Brit. and Tayl. (TAB. XVII.) Musc. Brit. p. 98. (excluding the synonyms of Web. and Mohr, Schwaegrichen, and Funk.) Bryum flavescens Dicks. Bryum lineare Dicks. Crypt. fasc. 3. p. 6. t. 8. f. 2. Hab. On wet rocks and stones, in shady rivulets, &c., especially near the spray of cascades. Fr. Oct. Nov. Growing in patches of a light-green colour, about 1 or 2 inches high. Leaves lanceolate, squarrose and straggling, somewhat sheathing below, slightly undulated in the margin, twisted or crisped when dry, keeled, usually with plane margins, entire or crenulate at the apex, distinctly papillose at the back, especially along the nerve, areola dot-like, nerve ceasing below the apex. Capsule on a rather thick wavy pale fruitstalk, cernuous, or in the var. y. quite erect, roundish, shortly ovate or oblong, destitute of a struma, its walls thick and firm, reddish-brown, at length blackish. Teeth of the peristome variable, sometimes scarcely cloven, sometimes with prominent bars. Lid large, conical at the base, with a longer or shorter oblique beak. Barren flowers capituliform, terminal, on a separate individual. The var. y. has longer and narrower leaves, sometimes only half as wide at the base as in D. pellucidum a., gradually tapering to a more acute point, and distinctly serrated; in some specimens not evidently papillose, and the teeth of the peristome narrower and longer. We have observed it growing in company with the typical form, but not intermixed; and although we confess that it is not easy to define the limits between the two forms, we are scarcely convinced as yet that they are only varieties of ore species. D. gracilescens Web. and Mohr, is an alpine species, perfectly distinct from D. flavescens. D. pellucidum has a remarkable aspect, and, on account of its short roundish capsule, seems scarcely to belong to the genus. Tridontium Tasmanicum Hook. fil. in Hook. Ic. Plant. t. 248. belongs to this genus, and is a closely allied species. It is no uncommon circumstance to find the teeth trifid in Dicranum. This occurs even in the smaller species, e. g. D. cerviculatum. 4. Dicranum squarrosum Schrad. (drooping-leaved ForkMoss); dioicous; stems elongated, dichotomous; leaves squarrose and recurved, lanceolate from a broad sheathing base, obtuse, concave, entire, nerve narrow, ceasing below the apex; capsule cernuous, ovate-oblong, scarcely strumose at the base; lid with a short beak. (TAB. XVII.) D. squarrosum Schrad. Journ. Schwaegr. Suppl. t. 47. Hab. In wet places among mountains, not common in fruit. Stems 1-3 inches long, forming loose bright-green patches. Leaves recurved, widely spreading, somewhat undulated, entire, margins plane, not papillose, scarcely altered or crisped when dry. Capsule on a thick reddish fruitstalk, its walls thick and firm, smooth when dry; the neck sometimes obscurely strumose, slightly constricted below the mouth. Annulus wanting. Barren-flowered plants with capituliform flowers. The most squarrose of the British Dicrana. It may be known from D. pellucidum, its nearest ally, by the broader, recurved, entire, not papillose leaves, scarcely changed when dry. Its aspect is peculiar, and in a barren state the stems are often 6 inches long. SECT. IV. CRISPA. 5. Dicranum Schreberi Hedw. (Schreber's Fork-Moss); dioicous; stems gregarious, subcaespitose, sparingly branched; leaves widely spreading from a broad sheathing base, suddenly lanceolato-subulate, carinate, subflexuous, margin denticulate; capsule ovate-oblong, cernuous; annulus none; lid shortly rostrate. (TAB. XXXIX.) D. Schreberi Hedw. Sp. M. t. 33. Bridel. Web. and D. recognitum Röhl. Bryum crispum Schreb. Angstroemia Schreberi C. Müller, Syn. Musc. 1. 438. Hab. On clayey or sandy soil by rivulets or ditches, &c., rare. Near Irlam, Lancashire, W. Wilson. Cheshire. Near Glasgow, Mr. G. J. Lyon. F. Oct. Nov. Stems-1 inch long, or more, forming loose light-green patches. Leaves suddenly contracted from a broad sheathing base, the upper portion narrowly lanceolate, wide-spreading and flexuose, somewhat crisped when dry, denticulate in the margin near the apex, nerve ceasing below the point; perichætial leaves larger than the rest. Capsule cernuous or suberect, shortly ovate or oblong, regular or slightly curved, smooth, reddish-brown, when dry somewhat contracted below the mouth. Lid large, conical at the base, shortly rostrate, about as long as the capsule. Barren flowers terminal on separate individuals. This species is a miniature resemblance of the preceding species, with narrower leaves, more suddenly dilated and sheathing below. It differs from the following in the inflorescence, and in the shorter lid. 6. Dicranum Grevilleanum Br. and Sch. (Greville's ForkMoss); monoicous; leaves from a wide sheathing base, suddenly lanceolato-subulate, wide-spreading and wavy, entire; capsule cernuous, ovate, substriated, substrumose; lid with a long beak. (TAB. XXXIII.) Br. and Sch. Bryol. Europ. Monogr. p. 19. t. 7. D. Schreberianum Hook. and Tayl. Musc. Brit. ed. 2. p. 95. Suppl. Tab. 3. Greville, Scot. Cr. Fl. t. 116. Hook. in Drummond Musc. Americ. No. 97. D. Schreberi var. Grevilleanum Bridel, Bryol. Univ. Angstroemia Grevilleana C. Müller, Syn. Musc. i. 439. Hab. Upon the ground in an old neglected road in Glen Tilt, at the foot of Ben-y-Gloe, on a clayey soil: Greville, Arnott, and Hooker, 1823. Not since observed in any part of the British Isles. Fr. Aug. Sept. Very like the preceding species, but differs thus: Leaves longer and narrower, entire, with narrower cellules and broader predominant nerve; capsule somewhat striated, slightly strumose at the base; lid longer than the capsule, with a longer beak; inflorescence monoicous ; growing in alpine situations where the true D. Schreberi is never found. It occurs in Switzerland, Italy, Germany, Sweden, and in North America. 7. Dicranum crispum Hedw. (curl-leaved Fork-moss); monoicous; stems gregarious, short; leaves subulate from a wide sheathing base, widely spreading and flexuose, crisped when dry; capsule erect, oval or obovate, striated, lid subulate. (TAB. XVII.) D. crispum Hedw. St. Cr. t. 33. Swartz. Turner. Smith, Angstroemia crispia C. Müller, Syn. Musc. i. 439. Fr. Oct. Nov. Growing in incoherent patches of a pale green colour. Stems short, scarcely branched, not inch high. Leaves not much crowded, widely spreading, subulate, or almost setaceous, wavy, with a suddenly dilated sheathing base, somewhat glossy, minutely denticulate, the nerve predominant above, crisped when dry. Capsule erect on a reddish fruitstalk about inch in length, of regular form, not strumose, furrowed when dry, oval or ovate-oblong. Annulus present. Lid conical at the base, with an oblique awl-shaped beak. This is readily distinguished from its allies by the very narrow crisped leaves, and erect symmetrical striated capsule. In the foliage it has some resemblance to Ceratodon cylindricus." Dicranum curvatum Hedw., a species not yet found in Britain, has the capsule somewhat irregular, and the leaves falcato-secund. SECT. V. RUFESCENTIA. 8. Dicranum varium Hedw. (variable Fork-Moss); dioicous; stems cæspitose, short, sparingly branched; leaves erecto-patent or secund, lanceolate, carinate, entire, scarcely toothed at the apex, margin reflexed, nerve subexcurrent, perichætial leaves scarcely sheathing; capsule oblique, rarely suberect, ovate or oblong, regular or incurved; lid large, shortly rostrate. (TAB. XVII.) D. varium Hedw. St. Cr. t. 34. Turner. Smith, Eng. D. rigidulum Swartz. Hedw. Sp. M. t. 32. Schwaegr. Angstroemia varia C. Müller, Syn. Musc. i. 435. var. B. tenuifolium; leaves narrower, obscurely nerved. D. subulatum Eng. Bot. t. 1273. var. y. tenellum; stem slender, scarcely branched, ascending; leaves falcato-secund, loosely cellular, remotely denticulate. var. d. callistomum; stem branched; leaves crowded, erectopatent, scarcely secund; capsule shortly pedicellate, erect, small, truncato-obovate, lid broadly conical at the base, almost as long as the capsule. D. callistomum Dickson, Crypt. fasc. 3. 5. t. 7. f. 10. Hab. On moist banks, &c., common. Fr. Nov. Dec. Growing in loosely aggregate patches of a rufous green colour. Stems scarcely inch long. Leaves lanceolate-tapering, suberect, more or less turned to one side, erect and straight when dry, the upper part carinate, with recurved margins, entire, or slightly toothed at the apex; perichætial leaves scarcely different from the rest. Capsule varying from ovate to oblong, and more or less oblique and incurved, slightly tumid at the base, smooth, its walls thick. Fruitstalk twisted to the right hand. Lid large, with a short beak. Annulus wanting. Peristome large, deep red, the teeth converging, deeply cloven. Barren-flowered plants more slender than the fertile ones. This species varies much according to soil and locality: var. y. in habit, in the shape and texture of the leaves, approaches to D. rufescens, but has the capsule, lid, and peristome as in the typical form of D. varium; var. d. is believed to be a form dependent on the luxuriant growth of the stem and innovations, and, though not of uncommon occurrence, is scarcely to be regarded as a constant variety. This is one of the commonest species of the genus. 9. Dicranum rufescens Turn. (reddish Fork-Moss); dioicous; stems gregarious, short, scarcely branched, suberect; leaves lax, secund, reddish, linear-lanceolate, margins plane, obscurely toothed, loosely reticulated; capsule erect, equal, ovate or obovate, slightly tumid at the base; lid conico-rostellate. (TAB. XVII.) D. rufescens. Turn. Musc. Hib. p. 66. Smith, Eng. D. varium ß. rufescens Hook. and Tayl. (TAB. XVII. |