138 A MANUAL OF MOSSES 



cespitose, persistent, mostly on soil or rocks, sometimes on 

 trees or rotting wood ; stem usually rounded-pentagonal, with 

 central strand, radiculose at least at base; leaves in several 

 series, below mostly small and remote, above larger and often 

 tufted, often bordered: costa mostly with 2-5 median guides, 

 often excurrent ; cells never papillose, upper prosenchymatous, 

 mostly rhomboidal or rhombic-hexagonal, rarely linear or 

 vermicular, basal rectangular to quadrate : seta elongate, erect, 

 smooth, more or less curved; capsule cernuous to pendulous, 

 sometimes erect, mostly symmetric, rarely arcuate, neither 

 striate nor plicate, ovate or pyriform, rarely almost globose; 

 collum evident, usually wrinkling when dry; annulus usually 

 present, large-celled, spirally deciduous ; peristome rarely none, 

 or simple, mostly double, the 16 teeth often bordered, hygro- 

 scopic, papillose on the exterior, especially towards the apex, 

 divisural line evident, trabeculse prominent; segments alternat- 

 ing with teeth, delicate, yellowish or hyaline, often with cilia, 

 often united below into a basal membrane; spores small to 

 medium ; operculum conic to convex, umbonate to apiculate or 

 rarely short-rostrate; calyptra cucullate, small, fugacious. 



A large and cosmopolitan family of about IS genera and 

 1,000 species. 



Key to the Genera. 



a. Leaf-cells narrow, upwards narrowly rhombic to linear. 



b. 

 a. Leaf-cells lax, upwards rhombic to hexagonal, never linear. 



c. 

 b. Leaves long-subulate; cilia prominently appendiculate. 



I. Leptobryum. 

 h. Leaves linear-lanceolate; cilia non-appendiculate, often rudi- 

 mentary or none. 2. Webera. 

 c. Annulus mostly none; leaves non-bordered. 



3. Mniobryuni. 

 c. .A.nnulus present; leaves often bordered. d. 



d. Sporogonia single; stem without rhizome-like stolons. 



4. Bryum. 



d. Sporogonia often several together; stems erect from rhizome- 

 like stolons. 5- Rhodobryum. 



1. LEPTOBRYUM (Schimper) Wilson. 



Synoicous or dioicous; paraphyses of the antheridial in- 

 florescence with an acuminate end-cell; no paraphyses in the 

 archegonial inflorescence: weak, cespitose in low, soft, lax, 

 yellowish-green tufts; stem erect, thin, brown-radiculose at 

 base ; lower leaves remote, small, lanceolate, uppermost leaves 

 much larger, tufted, erect to spreading, elongate-subulate from 

 a lanceolate base, canaliculate and often distinctly toothed to- 

 wards the apex; costa broad, flat, incomplete or percurrently 

 filling the apex ; cells very narrow and long, in the subulation 

 linear, the basal rectangular-elongate: seta short to long, very 



