446 



LESKEACEAE. 



1. Thuidium minutulum (Hedw.) Br. & Sch. 

 Minute Thuidium. (Fig, 491.) Stems up to 1' long, 

 very slender and creeping, branches short and simple, 

 somewhat irregular or pinnate; leaves minute, those of 

 the stems acuminate, sharply pointed, branch leaves 

 shorter, acute, more crowded; vein ending below the 

 apex, smooth; cells dense, obscure and papillose on both 

 surfaces; margins and apex with projecting multipapil- 

 late cells. Pedicel erect; capsule horizontal, cylindrie 

 or curved; lid long-beaked; annulus large; inner peri- 

 stome with cilia; spores small, maturing in autumn. 

 [Hypnum minutulum Hedw.] 



On rotten wood in shade, very rare in Bermuda ; not 

 uucommon in United States and Canada. 



Family 11. HYPNACEAE Hampe. 



Hypnum Family. 



Plants growing in loose or dense tufts, seldom floating; stems usually 

 decumbent and rooting, sometimes erect; branches regularly pinnate or 

 irregular; leaves straight or curved, erect, spreading or seeund, usually 

 symmetric; vein either lacking, single or double; cells mostly much longer 

 than wide, smooth or papillose, those of the basal angles often different 

 in shape and size. Pedicel more or less elongated and exserted; capsule 

 mostly horizontal, often curved and unsymmetric; peristome double; seg- 

 ments keeled; cilia usually present; spores small. A large family, widely 

 distributed in all parts of the globe. Composed of about 37 genera with 

 over 960 species. 



Vein of the leaf long, single ; lid of the capsule conic, blunt. 1. Amhlystegium. 



Vein of the leaf short and double or none ; lid of the capsule 



sharp-pointed. 2. Isopterygiiim. 



1. AMBLYSTEGIUM Bruch & S chimp. 



Plants usually growing in moist localities; stems irregularly branched; 

 branches slender; leaves symmetric, spreading; vein single; cells smooth, not 

 much longer than wide. Pedicel erect, smooth; capsule usually curved; calyptra 

 cucullate; lid conic; annulus present; peristome double. [Greek, referring to 

 the blunt lid.] A genus of 47 species, widely distributed in America and 

 Europe. Type s]iecies : Hypiium riparium L. 



