Plagiochasma rupestre (J. R. Forst. & G. Forst.) Steph.

Plagiochasma rupestre (Forst.) Stephani, Bull. Herb. Boissier 6: 783. 1898.
Aytonia rupestris Forst, Char, Gen. PL 148. 1776.
? Rupinia lichenoides L. f. Suppl. 69. 1781.
Rupinia rupestris Sw. Meth. Muse. 39. 1781.
RebouUa maderensis Raddi, Giorn. Sci. Lett. Arti— . My 1821.— Mem. Soc. Ital. Modena 20: 3.
1829. Sedgwickia kemispkaerica Bisch. Nova Acta Acad. Leop. -Carol. 17: 1079. 1835. Not S. hemi-
sphaerica Bowdich, 1825. Plagiochasma Aitonia Lindenb. & Nees; Nees, Natiug. Eur. l^eberm, 4: 41. 1838. Anirocephalus italicus Sassi, Atti Riun. Sci. Ital. 1: 160. . 1840.
Jungermannia (Fegatella) ausiralis Tayl.; Hook. f. & Tayl. Lond. Jour. Bot. 3: 572. 1844. Jungermannia (Fegatella) limbata Tayl.; Hook. f. & Tayl. Lond. Jour. Bot. 4: 95. 1845. Plagiochasma australe Nees; G. L. N. Syn. Hep. 515. 1846. Plagiochasma limhatum Nees; G. L. N. Syn. Hep. 516. 1846. Plagiochasma elongatum Lindenb. & Gottsche; G. L. N. Syn. Hep. 519. 1846. Plagiochasma mexicanum Lindenb. & Gottsche: G. L. N. Syn. Hep. 519. 1846. Plagiochasma italicum De-Not. Mem. Accad. Torino II. 18: 476. 1859. Aytonia italica Lindb. Not. Sallsk, Faun. Fl. Fenn. 9: 291. 1868. Otiona rupestris Dumort. Hep. Eur. 148. 1874. Otiona italica Vumort. Hep. Eur. 149. 1874. Rupinia italica Trevisan, Rend. 1st. Lomb. II. 7: 785. 1874. Rupinia mexicana Trevisan, Mem. 1st. Lomb. 13: 437. 1877. Rupinia elongata Trevisan, Mem. 1st. Lomb. 13: 437. 1877. Rupinia limbata Trevisan, Mem. 1st. Lomb. 13: 437. 1877. Rupinia australis Trevisan, Mem. 1st. Lomb. 13: 437. 1877. Aytonia lanigera Spruce, Trans. Bot. Soc. Edinb. 15; 568. 1885. Aytonia australis Stephani, Hedwigia 28: 129. 1889. Aytonia elongata Underw. Bot. Gaz. 20; 66. 1895. Aytonia mexicana Underw. Bot. Gaz. 20; 66. 1895. Plagiochasma lanigerum Stephani, Bull. Herb. Boiss. 6: 788. 1898. Aytonia Evansii Haynes, Bull. Torrey Club 34: 57. 1907.
Thallus pale-green and glaucous, pigmented with purple below and along a narrow border above, mostly 1-2 cm. long and 5-7 mm. wide, with a broad rounded keel and plane or slightly canaliculate on the upper surface; branching sometimes dichotomous, sometimes ventral, often with apical innovations; epidermal cells mostly 18-30 m in diameter, with small trigones and a waxy cuticle; pores not elevated and very inconspicuous, surrounded usually by a single circle of 4-6 cells, the radial walls often somewhat thickened; green tissue fairly compact; ventral scales deep-purple with one or two, rarely three ovate-lanceolate to lanceolate appendages, acute to acuminate, entire, and slightly or not at all constricted at the base, Paroicous or autoicous; male receptacle sometimes borne on the same branch as the female, sometimes on a more or less elongate male branch ; female receptacles borne singly or in a median longitudinal series, the stalk usually only 3 mm. long or less, the disc mostly 2-3 mm. wide, concave, with (usually) 2 or 3 apiculate lobes,the paleae abundant, narrowly subulate with elongate filiform points, entire ; spores yellowish-brown, 70-90 ju in diameter, minutely rugulose with regular though often incomplete networks on the faces, the meshes mostly 15-20 ju wide; ■elaters about 10 m wide, with 2-4 spirals, sometimes more or less coalescent.
Type locality: Madeira.
Distribution: New Mexico and Arizona, south into Mexico; Jamaica; also in South America, Europe, the Atlantic Islands, Africa, Asia, and Australasia.

Plagiochasma rupestre là một loài rêu trong họ Aytoniaceae. Loài này được G. Forst. Stephani mô tả khoa học đầu tiên năm 1898.