TORTULACEAE. 483 



cells; upper part of leaf with small green, obscure and papillose cells, extend- 

 ing a short distance down each side of the hyaline base ; margins above with a 

 narrow pale border of 2-3 rows of elongated smooth clear cells, mostly entire 

 except at the spinosely toothed apex; costa also spinose on back toward the 

 apex. Dioicous. [Seta slender, about 5 mm. long; capsule narrow, about 2 

 mm. long with a slender beaked lid; calyptra cucullate, its tip rough; teeth 

 narrow.] 



Onlv a few small sterile plants found at Xicholl's Town, Andros : Cuba ; Ja- 

 maica ; Porto Rico and Guadeloupe to Brazil. Gaudichaud*s Sykrhopodon. 



Family 4. TORTULACEAE Lindb. 



Tortula Family. 



Plants scattered or crowded into tufts, sometimes minute and ephem- 

 eral, with indehiscent capsules. Stems simple or branched; leaves usu- 

 ally crowded, sometimes forming rosettes at the apex of the stems, generally 

 twisted when dry. lanceolate or oblong and hyaline at base often with a 

 broader and denser apex; vein single, stout usually percurrent or some- 

 times excurrent into an awn ; margins frequently recurved, entire, crenu- 

 late, or rarely serrulate ; cells longer and smooth at base, smaller and denser 

 or papillose at apex. Heteroicous. Pedicel terminal, more or less exserted 

 and erect; capsule erect or inclined; peristome rarely double or lacking, 

 usually single, of 16 narrow, often bifid teeth, sometimes long and twisted 

 with a more or less exserted basal membrane; lid conic or beaked; calyptra 

 cucullate; spores small. A large family of 46 genera and about 400 

 species widely distributed in all parts of the world. Sometimes called 



POTTIACEAE. 



A. Fruit on elongated erect pedicels ; capsules erect. 

 Peristome single ; annulus double. 



Teeth oblique, twisted once or twice. 1. Tortula. 



Teeth erect, not twisted. 2. Oyrow< teia. 



Peristome and annulus none. 3. Hymeno8tomum. 



B. Fruit unknown in the Bahamas. Propagating by brood- 



bodies, borne in the axils of the upper leaves, or the 



brood-bodies unknown. 

 Upper cells of leaves mamillose on upper surface only. 



Costa stout, ending below the denticulate apex. 4. Hyophila. 



Costa tapering to the acuminate apex. 5. Desmatodon. 



Upper cells of leaves papillose on both surfaces. 



Margins tint or revolute at base, denticulate at apex. 6. Barbula. 



Margins inrolled, entire. 7. Trichostomum. 



1. TORTULA Hedw. Fund. Muse 2: 92. 1782. 



Plants of various sizes, sometimes large and stout ; usually growing on the 

 ground or on rocks, scattered or in cushions. Stems usually simple, rarely 

 branched; with the leaves often crowded in a rosette at the top of the stem, 

 usually spreading when dry, or twisted, mostly broader above the middle; mar- 

 gins usually entire; vein single, sometimes excurrent into an awn; basal cells 

 long, clear and smooth, the upper small and dense, generally papillose. Pedicel 

 erect, elongate; capsule erect, cylindric ; lid usually long-beaked; calyptra 

 cucullate; peristome single, usually twisted, arising from a basal membrane; 

 teeth 16 or 32, slender, papillose; spores small. [Latin, with reference to the 

 twisted peristome.] A large genus of 186 species widely distributed in all 

 parts of the world. Type specie-: Bryum murale L. 



