ORTHOTBICHACEAE. 487 



leaves. [Dioicous. Pedicels erect, about 1 cm. long, twisted when dry; cap- 

 sules up to 1 mm., erect, eylindric; lid beaked; calyptra cucullate, rough at 

 apex; peristome red, twisted; teeth slender, bifid and papillose, with a short 

 basal membrane; annulus none; spores smooth, small, ripening in summer.] 



On wet rocks in quarry at Nassau: Florida; Louisiana; Cuba; Jamaica; I'orto 

 Rico to Trinidad and South America. CltUGEB'S Baublla. 



7. TEICHOSTOMUM Hedw. Fund. 2: 90. 1782. 



Plants medium-sized, usually crowded. Stems erect, simple or branched. 

 Leaves curled and twisted when dry, larger at base than above, with a narrow 

 sharp apex; margins flat or inrolled, entire; vein single, usually percurrent; 

 basal cells oblong and clear; upper cells denser, small and papillose on both 

 surfaces. Pedicel erect, elongate ; capsule erect, eylindric ; peristome single ; 

 teeth 16, either entire or divided to base, usually papillose; lid conic-beaked; 

 calyptra cucullate. [Greek, in reference to the narrow teeth.] Widely dis- 

 tributed in various temperate and tropical regions. Type species: Weisia 

 cylindrica Bruch. 



1. Trichostomum rivale (Mitt.) Jaeg. Adumb. 1: 2-45. 1871-72. 



Tortula rivalis Mitt. Journ. Linn. Soc. 12: 147. 1869. 



Plants in dense bright green or yellowish cushions. Stems up to 5-10 mm. 

 high, usually simple ; leaves crowded, curled and twisted when dry, 2-3 mm. 

 long, base erect, clasping, the tips narrower and spreading when moist; vein 

 smooth, excurrent into the mucronate apex; margins entire, incurved above the 

 middle; basal cells lax with longer cells on the margins, extending up the blade 

 to the papillose cells of the tip ; upper cells densely papillose on both sur- 

 faces. Only found sterile in the Bahamas. Dioicous. [Pedicel yellow, erect, 

 15-20 mm. long; capsule 2-3 mm. long, erect, eylindric; calyptra cucullate; 

 lid conic-beaked; peristome single, of 16 slender, erect or slightly twisted, 

 papillose, bifid teeth, often disappearing and leaving only a ragged membrane; 

 spores rough, brown, maturing in spring.] Very closely related to Tricho- 

 stomum jamaicense Mitt. 



On rocks and in pine-barrens, Marsh Harbor, Abaco: Cuba; Jamaica and Porto 

 Rico. Rock Trichostomum. 



Some poor sterile specimens of a Trichostomum were collected in New Provi- 

 dence, by L. J. K. Brace, in June, 1918, Number 9509. The leaves are less papillose 

 than in T. rivale and the plants may represent another species, T. involutum Sull. 



Family 5. ORTHOTRICHACEAE Bruch & Schimper. 



Orthotrichum Family. 



Plants growing in dense dark green mats. Stems erect or creeping, 

 often branching and interlacing; branches short, erect, densely leafy. 

 Leaves curled and twisted when dry. crowded, lanceolate or oblong; costa 

 single, percurrent or excurrent into a mucronate tip; cells dense, small, 

 obscure, smooth or papillose, basal often longer and smooth. Pedicel 

 short, terminal; calyptra large, campanulate, plicate and lacerate at base, 

 smooth, hairy, or rough at apex; lid usually beaked; capsule smooth or 

 ribbed; peristome single or double, seldom lacking. Twelve genera and 824 

 species, widely distributed. 



Calyptra plicate, Bmooth; peristome lacking. 1. Hacromitrium, 



Calyptra doI plicate, rough at apex ; peristome double. '-'. Schlotheimio. 



