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, cylindric 

 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 

 uncommon 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 secund, 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. Amblystcyium. 



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



sharp-pointed. 2. Isoptcryglum. 



1. AMBLYSTEGIUM Bruch & Schimp. 



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 species: Hypnum riparium L. 



