488 ORTHOTEICHACEAE. 



1. MACROMITRIUM Brid. Mant. Muse. 132. 1819. 



Plants in dense dark mats, usually on trees. Stems creeping with erect 

 branches; leaves crowded and usually twisted when dry; vein single, percur- 

 rent or excurrent, rarely ending below the apex; margins entire or rarely 

 toothed at apex, not bordered, except occasionally at base; cells small and 

 dense in the upper part of the leaf smooth or papillose, larger and clearer 

 below. Pedicel exserted or rarely immersed, terminal ; capsule erect, ovoid, 

 urn-shaped or cylindric; lid beaked; calyptra campanulate and lacerate at 

 base, smooth or hairy. [Greek, in reference to the large calyptra.] A large 

 genus of 385 species, common in tropical regions of both hemispheres. Type 

 species: Schlotheimia acicularis Brid. 



* 



1. Macromitrium mucronifolium (Hook, et Grev.) Schwaegr. Supp. 2 2 : 61. 

 pi. 170. 1826. 



Orthotrichum mucronifolium Hook, et Grev.; Brewst. Edinb. Jour. 1: 116. 

 pi. 4. 1824. 



Plants in dense dark green mats. Stems creeping and matted together by 

 a brown felt of rhizoids, the branches erect, short, seldom more than 2-3 mm. 

 high; leaves spirally twisted when dry, spreading when moist, crowded and 

 numerous, carinate, oblong; apex blunt or sometimes notched; vein ending in 

 a short cuspidate tip ; upper cells dense, small, opaque, with thickened swollen 

 walls; base bordered by 3-4 rows of longer and clearer cells. Pedicels erect, 

 about 5 mm. long; capsule about 1 mm., ovoid and tapering at base, with a 

 long neck, slightly ribbed when old; calyptra covering the capsule, ribbed but 

 not hairy; lid beaked; peristome and annulus none; spores nearly smooth. 



On trees in coppices, Andros and Abaco : Florida and the West Indies to trop- 

 ical South America. Mucronate Macromitricsi. 



2. SCHLOTHEIMIA Brid. Sp. Muse. 2: 16. 1812. 



Plants in dense dark mats, usually on trees. Stems creeping, with numer- 

 ous crowded and usually short simple branches. Leaves crowded, erect or 

 spreading, often spirally twisted when dry; vein single, stout, percurrent or 

 excurrent; margins usually entire and not bordered; upper cells much thick- 

 ened, usually oblique, smooth or rarely papillose, the lower rectangular, less 

 thickened and vertical, smooth. Pedicel exserted or immersed, terminal on the 

 branches ; capsule ovoid or cylindric ; peristome double, the inner shorter than 

 the outer, often rudimentary; lid beaked; calyptra not ribbed, usually lobed at 

 base, sometimes hairy. [Named for Ernest Schlotheim.] A genus of about 

 120 species, mostly tropical or subtropical. Type species: Hypnum torquatum 

 Hedw. 



1. Schlotheimia Sullivantii C. Muell. Syn. Muse. 1: 756. 1S49. 



Plants in dense wide dark green or brown mats. Stems creeping and 

 densely hairy with brown radicles; branches short, erect, crowded; leaves 

 also densely crowded, 1-1.5 mm. long, oblong-lanceolate; apex blunt; vein end- 

 ing in a short abrupt tip ; upper part of the leaf undulate, the cells thickened 

 and hexagonal, those of the lower part clearer, oblong, not bordered. Pedicel 

 erect, about 5 mm. high ; capsule 2-3 mm. long, cylindric, smooth or ribbed 

 when dry; peristome double, deeply inserted, rim of 7-8 rows of cells, annulus 

 none; the outer teeth recurved and papillose, longer than the inner ones; lid 



