LEUCOBRYACEAE. 479 



b Capsules horizontal or curved. 



* Leaves minutely papillose, on the back. 

 Papillae single and central on each cell. 



Haplocladium in Fam. 12. Leskeaceae. 

 Tapillae single and terminal at the end of each cell. 



HitteiiotluiHiiiiuiii in Fam. 13. Hypnaceae. 

 Papillae several in a row in the middle of each cell. 



Taxithclium in Fam. 13. Hypxaci: ae. 

 ** Leaves not papillose, the cells smooth. 



t Leaves uniform and regular ; alar cells enlarged. 

 Vein lacking or short and double. 



Peristome teeth without deep lamellae on the inner surface. 



Isopterygium in Fam. 13. Hypnaceae. 

 Peristome teeth with deep lamellae, especially at base. 



Sematophyllum in Fam. 14. 'Seiiatophyllaceae. 

 Vein single, ending in the middle of the leaf. 



Arnblystegium in Fam. 13. Hypnaceae. 



tt Leaves of two kinds, the lateral shorter and broader; alar cells not 



enlarged. Vesicularia in Fam. 13. Hypxaceae. 



Family 1. LEUCOBRYACEAE C. Muell. 



White Moss Family. 



Plants perennial, growing in dense pale green cushions; stems medium 

 to large, branching; sometimes fragile and breaking off (thus propagating 

 asexually) ; leaves crowded, vein broad, filling most of the leaf, the green 

 cells of the leaf small, in a single central band between several layers of 

 larger hyaline cells; blade very narrow, sometimes lacking. Pedicels erect, 

 terminal; capsule erect or horizontal, regular or irregular; peristome single, 

 teeth 8 or 16 ; lid beaked ; calyptra cucullate. Nine genera and 229 species 

 are known. (Named in reference to their pale green color.) 



Leaves four times longer than wide, incurved, apex concave and 



lanceolate. 1. Lcucobryum. 



Leaves ten times longer than wide, recurved, apex fiat, oblong- 



apiculate. 2. Octoblcphantm. 



1. LEUCOBRYUM Hampe, Flora 20: 282. 1837. 



Characters of the family. A genus of 121 species, widely distributed in- 

 temperate and tropical regions. [Greek, in reference to the pale color of the 

 plants.] Type species: Leucobryum glaucum (L.) Sehimp. 



1. Leucobryum albidum (Brid.) Lindb. Oefv. Sv. Vet. Akad. Forh. 20: 403. 

 1863. 



Bicranum albidum Brid. Muse. Rec. 2 1 : 167. 1798. 



Leucobryum glaucum albidum Cardot, Rev. Bryol. 38: 80. 1911. 



Plants in dense, pale green cushions, seldom more than 3 cm. high; stems 

 crowded with branches; leaves numerous at the ends of the branches, incurved 

 and concave when dry, spreading when moist from the base to a narrower eon- 

 cave point, 2-4 mm. long, ending in a sharp apex, the basal blades short, form- 

 ing a narrow, colorless border of 3-5 rows of cells; the vein composed of 24 

 layers of large hexagonal clear cells with a central band of small green quad- 

 randular cells. [Capsule terminal, on a slender pedicel, curved and furrowed 

 when dry; lid beaked; teeth split to the middle; calyptra cucullate.] 



Only found once, sterile, growing on rotten wood and logs in coppices. Conch 

 Sound, Andros, New Jersey to Florida and Louisiana: Cuba: llispaniola; Mexico 

 and Guatemala. White Moss. 



