with an oblique beak; annulus none; teeth of the peristoine in unequal pairs. (TAB. XLI.) T. crispulum Bruch and Müller, in Regensb. Bot. Zei- Didymodon crispulus Wilson in Suppl. Eng. Bot. t. 2734. Plaubelia tortuosa Bridel, Bryol. Univ. i. p. 522. var. B. brevifolium; densely caespitose; stems more slender; leaves shorter, lanceolate-acuminate, mucronulate; capsule smaller. var. y. angustifolium; densely caespitose; stems shorter; leaves more crowded, narrowly linear-lanceolate, apiculate; teeth of the peristome more regularly paired. T. viridulum Bruch and Müller, 1. c. t. 5. Mougeot and Hab. Limestone rocks and banks near the sea. Ormeshead, Caernarvonshire; and near Tros-y-Marian, Anglesey, W. Wilson. Near Bristol, Mr. Thwaites. Probably not unfrequent in similar situations, but rare in fruit. Fr. June, July. Stems growing in bright green rather dense patches, from 3 lines to 1 inch long, or more. Lower leaves smaller, more distant, lanceolate; upper leaves longer, and crowded into a terminal tuft, spreading, crisped and intorted when dry, linear-lanceolate, concave, the margin somewhat undulated and incurved, obtuse and somewhat boat-shaped or cucullate at the apex, with a small mucro formed by the projecting nerve. By this character, and by the more evident peristome, this species is distinguished from the next species, which it much resembles. 2. Trichostomum mutabile Bruch (variable Trichostomum); leaves broader, lanceolate or ligulate, spreading, crisped when dry, margin plane and slightly undulated, the nerve projecting into the straight mucro; capsule ovate; lid rostrate; annulus none; teeth of the peristome very short and irregular. (TAB. XLI.) T. mutabile Bruch MS. De Not. Br. and Sch. Monogr. p. 8. t. 5. T. brachydontium Bruch, 1. c. t. 3. Didymodon brachydontius Wilson, Suppl. Eng. Bot. t. 2735. Gymnostomum tortile Taylor, in Fl. Hib. ed. 2. Tortula humilis Miss Hutchins, in Herb. Turner. var. ß. densum; densely cæspitose; leaves shorter, lanceolate. Hab. On moist or shady banks in calcareous soil, and in the crevices of calcareous rocks, generally near the sea. Caernarvonshire, and Anglesey, with the preceding species; also on moist rocks in the Gap of Dunloe, and in other situations near Killarney, Ireland, W. Wilson. Near Kenmare, &c., Dr. Taylor. Sussex, Mr. Borrer; rarely in fruit. Fr. June, July. Much resembling the last species in size and general appearance. Foliage of a brighter green. Leaves broader, flatter, not at all cucullate at the apex, the nerve not being incurved but straight when the leaf is seen in profile; they are more or less spreading, crisped and intorted when dry, the upper ones ligulate, somewhat undulated in the margin, which is plane, the strong nerve forming a prominent mucro at the apex. Capsule erect, regular, ovate-oblong or oval, reddish-brown. Fruitstalk yellowish, inch long. Lid rather shorter than the capsule, obliquely rostrate. Peristome extremely irregular and fugacious, the teeth unequal, connected by a narrow basilar membrane, sometimes paired, often very short and inconspicuous, erect, pale or reddish, smooth or granulated. It is distinguished from Gymnostomum tortile by its more robust habit, and by the planemargined leaves. It is closely allied to Trichostomum flavo-virens Bruch, which chiefly differs in the longer, pale, thin capsule, and the elongated regularly formed peristome. 3. Trichostomum tophaceum Bridel (bluntish-leaved Trichostomum); stems densely cæspitose, branched, and fasciculate; leaves spreading from an erect base, lanceolate, rather obtuse, the nerve ceasing below the apex, carinato-concave, margin recurved; capsule erect, regular, oblong, subcylindrical; annulus none; lid obliquely rostrate; teeth of the peristome irregular, cohering in pairs. (TAB. XX.) T. tophaceum Bridel, Mant. Musc. and Bryol. Univer. T. linoides Smith, Eng. Bot. t. 2295. (not Bryum linoides. T. lineare Smith, Eng. Bot. t. 1598. (not B. lineare Dickson). De Notaris. Davies, Wel. Bot. p. 108. T. trifarium Smith, Eng. Bot. t. 1707. Anacalypta tophacea Nees and Hornsch. Bryol. Germ. t. 37. f. 5. Didymodon trifarius Hook. and Tayl. Dill. Musc. t. 47. f. 30. fide Hooker and Arnott. var. B. brevifolium; leaves rather acute, broader. Bryum brevifolium Dickson, Crypt. ii. 4. Hab. On moist rocks, and in wet sandy or clayey places. Very common near Warrington, W. Wilson. Near Glasgow. Yorkshire, Mr. Spruce. Sussex, Mr. Mitten. Fr. Nov. Stems 1 inch high, of a dull deep green colour. Leaves spreading when wet, somewhat twisted when dry, the upper ones (especially those of the perichætium) obtuse, by which character, and by the abbreviated nerve, this species is readily distinguished from T. rigidulum. It differs also from that species in the absence of an annulus. The peristome is quite variable. In small dwarfish forms of the species, the teeth seem to be reduced to 16, while in other states there are 32 paired teeth: they are always connected by a basilar membrane which rises somewhat above the orifice of the capsule; and though the teeth are often rather fugacious, the species may by this character be always distinguished from Didymodon luridus, a moss which was entirely unknown in Britain when the 2nd edition of Muscol. Brit. was published, and is therefore incorrectly cited by Bruch and Schimper. There is great confusion between Bryum lineare and linoides of Dickson, in consequence of his having reversed the names of the specimens sent to Smith and Turner. B. lineare of Dickson is a tall variety of Dicranum pellucidum, and his B. linoides a variety of Tortula unguiculata; but Trichost. linoides of Eng. Bot., sent from Teesdale by Mr. Backhouse, is an unusually tall state of T. tophaceum; T. lineare of Eng. Bot. is the ordinary state, from Mr. Winch; and T. trifarium of Eng. Bot. is the smallest state of the species with simple teeth (Grimmia obtusifolia Turner, MSS. in Herb. Turn.), sent from Clapham Springs by Dr. Abbot. Swartzia trifaria of Hedwig (St. Crypt. ii. t. 28.) is not cited as a synonym, because, in the absence of authentic specimens, it is impossible to identify it with our moss; and Hedwig describes the barren and fertile flowers as being upon the same receptacle, giving reason to suspect that he had Didymodon rubellus in view at the time. The remarks of Smith in Eng. Bot. on this point are quite inconclusive, he having mistaken the paraphyses of T. trifarium for "stamens." 4. Trichostomum rigidulum Smith (rigid-leaved Trichostomum); stems loosely cæspitose, or densely tufted; leaves spreading, or recurved, lanceolate, carinate, margin recurved, nerve subexcurrent; capsule cylindrical or oblong-ovate, with an annulus; peristome rather long, variable. (TAB. XX.) T. rigidulum Smith, Fl. Brit. p. 1238. Eng. Bot. 2178. Web. and var. B. densum; stems shorter, tufted; capsule elliptic-oblong; calyptra larger; lid with a longer and more slender beak. Desmatodon rupestris Funck, in Bridel, Bryol. Univ. (ex parte). Didymodon rigidulum Hook. and Tayl Tortula imberbis Smith, Eng. Bot. t. 2392.? (not Dill. Hab. On moist rocks, especially near waterfalls. Var. 6. on Stems about an inch high, much shorter in the var. B., of a dull tawny green, simple or branched. Leaves erecto-patent, or spreading and recurved, lax and slightly crisped when dry; upper ones oblonglanceolate, recurved in the margin, keeled, the nerve not ceasing below the summit; areolation dot-like. Capsule erect, long and cylindrical in the typical form, shorter and oval-oblong in the var. B., reddish-brown, on a fruitstalk -1 inch in length. Lid half as long as the capsule, obliquely rostrate. Teeth of the peristome connected by a basilar membrane, mostly united in pairs, pale reddish, granular, erect when dry. Annulus fragmentary. The tall typical state of this moss might easily be mistaken for Tortula fallax. It is the moss mentioned in Hook. Eng. Fl. vol. v. p. 29., found near Beaumaris by Mr. Wilson. The var. B. is the form regarded as the type of the species in Musc. Brit., and this has sometimes been mistaken for Tortula gracilis, and at other times has been confounded with T. fallax. Due attention to the peristome will obviate such mistakes. Tortula imberbis of Smith, figured in Eng. Bot., is doubtful. Specimens from Dickson, and from the Dillenian Herbarium (Musc. t. 48. f. 46.), named as such by Smith, in Herb. Turner, appear to belong to Didymodon rubellus; but Mr. Eagle's specimens, in the same Herbarium, belong to Trichostomum rigidulum var. ß. SECT. II. Leaves subulate from a lanceolate base. SUBULIFOLIA. Leptotrichum Hampe. A. Inflorescence dioicous. 5. Trichostomum tortile Schrad. (twisting Trichostomum); stems short, loosely cæspitose, simple or branched, subflexuose; leaves secund, or spreading every way, lanceolato-subulate, curved, margin reflexed, nerve excurrent; capsule erect, cylindrical, regular or curved; lid with a short beak; annulus simple; peristome variable. (TAB. XLI.) T. tortile Schrad. Schwaegr. Suppl. t. 35. Bridel. Br. and Sch. Monogr. p. 14. p. 10. Didymodon tortilis W. Arnott. De Notaris. Dicranum tortile Web. and Mohr. Bot. Tasch. t. 7. f. 12, 13. Leptotrichum tortile C. Müller, Syn. Musc. i. 454. var. B. pusillum; leaves shorter; capsule oval-oblong; peristome shorter. Trichostomum pusillum Hedw. St. Cr. t. 28. f. 2, 4, 9, 10. Bridel. Web. and Mohr. Barbula curta Hedw. St. Cr. t. 31. Schultz. Desmatodon curtus Bridel. Hab. Sandy banks, quarries, &c.; rare. Near Belfast, Ireland, T. Drummond. Near Castle Howard, Yorkshire, Mr. Spruce. Near Hurst Pierpoint, Sussex, Mr. Mitten. Fr. Oct. Nov. Stems short, gregarious. Leaves mostly secund, somewhat falcate, straight or very slightly twisted when dry, narrow, lanceolato-subulate, carinate, margin for the most part reflexed, slightly toothed at the apex. Perichætial leaves larger, and sheathing below. Capsule on a straight reddish pedicel, small, subcylindrical, pale reddish-brown, with a red orifice, the walls rather thin. Lid about of the length of the capsule, conical-acute or rostellate. Teeth of the peristome purplish red, erect or inclined to one side, more or less incurved when dry, varying in length and in the degree of union of each pair, shorter and more imperfect in the var. p. A smaller and much rarer species than T. homomallum, with shorter and broader leaves, much resembling those of Dicranum varium, to which species Mr. Mackay's specimens in Herb. Turn. belong. Bryum pusillum of Dickson, in Herb. Turner, appears to be a variety of Weissia controversa with long and very narrow leaves (not Tortula linearis), and is very different from Trichostomum pusillum of Hedwig. 6. Trichostomum flexicaule Br. and Sch. (wavy-stemmed Trichostomum); stems elongated, densely caespitose, dichotomously-branched and fastigiate, flexuose; leaves spreading or secund, lanceolato-subulate, concave, glossy, denticulate at the apex, nerve broad and predominant; capsule erect, ovateoblong, small, with an annulus; lid shortly rostellate; teeth of the peristome rather long and unequal. (TAB. XLII.) Bryol. Europ. Monogr. p. 15. t. 11. Cynodontium flexicaule Schwaegr. Suppl. t. 29. D. longirostris? Hooker in Eng. Fl. vol. 5. Leptotrichum flexicaule C. Müller, Syn. Musc. i. 449. var. B. densum; more compactly cæspitose; leaves straighter. Hab. On calcareous rocks, &c.; not unfrequent on the Scottish mountains, and in Derbyshire, &c., but always barren in Britain. Fr. June. Growing in glossy yellowish-green tufts, 1-3 inches high or more. Stems slender, fragile, flexuose, beset with radicular fibres. Leaves somewhat crowded, usually secund, flexuose when dry, glossy, yellowish, lower ones brownish, lanceolato-subulate, longer than in the preceding species and more setaceous, with a broader predominant nerve, concave, margin plane, the base narrower than the part above; perichætial leaves larger, sheathing. Capsule small, brownish. Annulus compound. Peristome fugacious, the teeth unequal, granulose, here and there anastomosing at the base. 7. Trichostomum homomallum Br. and Sch. (curve-leaved Didymodon); stems cæspitose, short, dichotomous; leaves subulato-setaceous, nerve broad, predominant; perichætial leaves sheathing; capsule erect, ovate-oblong, with an annulus; lid short, conical, obtuse; peristome variable, the basilar membrane very short. (TAB. XX.) Bryol. Europ. Monogr. p. 16. t. 12. (nerve of leaf too narrow, the base too much dilated). Didymodon homomallum Hedw. Sp. Musc. t. 23. Schwaegr. D. heteromallum Hook. and Tayl Weissia heteromalla Hedw. St. Cr. t. 8. Bridel. |