J UNGERMANNIACEAE. 



457 



Leaves bifid. 



Leaf-cells large, measuring 30-50 # in diameter ; 



plants pale green. 2. Ceph<il>,:i,i. 



Leaf-cells minute, measuring 20 # in diameter or 



less ; plants dark green or reddish. 3. 



2. Leaves incubous, undivided or slightly bifid. 5. 



B. Leaves deeply divided into hair-like lobes. 6. 



C. Leaves deeply bilobed and complicate, the ventral lobe, or 



lobule, smaller than the dorsal and usually specialized as 

 an inflated water-sac. 



1. T'nderleaves none. 



Plants large, perianth flattened and with a broad trun- 

 cate mouth. 7. 

 Plants minute, perianth abruptly contracted to a small 



tubular mouth. 

 Perianth inflated, five-keeled. 



Perianth flattened, the two lateral keels sharp and 

 distinct. 9. 



2. Underleaves present. 



Lobule inflated but not helmet-shaped, attached to the 



dorsal lobe by a long keel. 

 Margin of dorsal lobe entire or nearly so. 

 Perianth inflated, sharply five-keeled. 



Plants pale green and delicate. 10. 



Plants yellowish green and firm. 12. 



Perianth flattened, the two lateral keels sharp. 11. 

 Margin of dorsal lobe crenulate from projecting 



cells. 



Lobule normally inflated, helmet-shaped, with a stalk- 

 like base, keel usually very short. 

 Subfloral innovations (borne just behind the Inner- 

 most perichaetial bracts) present. 14. 

 Subfloral innovations absent. 15. 



Calypoyeiu. 

 Tclaranea. 



Rudula. 



Cololejeunea. 

 Leptocolea. 



Lejeunea. 



Euosmolejeunea. 



Rcctolejeuncu. 



13. Crossotolejeiiin 'i. 



Jubula. 

 Frullania. 



1. PLAGIOCHILA Dumort. 



Stems ascending from a prostrate rhizome, simple or with lateral branches. 

 Leaves succubous, undivided, decurrent dorsally and ventrally, the margin 

 varying from entire to ciliate or spinose. Underleaves usually minute anil 

 short-lived. Inflorescence dioecious. Antheridia from one to ten in the axils 

 of bracts saccate at the base, the bracts 

 imbricated and usually arranged in elon- 

 gated androeeia often proliferating at 

 the apex. Perichaetial bracts similar to 

 the leaves but often broader and more 

 toothed. Perianth laterally compressed, 

 the mouth broad, truncate, and variously 

 dentate to ciliate. [Greek, oblique lip.] 

 Some 800 species or more, mostly tropical. 

 Type species: P. asplenioides (L.) Dumort. 



1. Plagiochila Smallii Evans. 



SMALL'S PLAGIOCHILA. (Fig. 503.) 

 Loosely tufted, usually dark green. 

 Stems sparingly and irregularly 

 branched. Leaves obliquely spreading, 

 distant, the largest about li" long and 

 i" wide, narrowly ovate to ligulate, 

 truncate at the apex, sharply 6-12- 

 toothed ; perianth campanulate, sharply 

 spinose-ciliate at the mouth. 



On moist rocks. Paynter's Hill and 

 Paynter's Vale. Known also from tropical 

 Florida. 



