AMBLYSTEGIUM. 213 



Walls, moist banks, trees, &c. Common. 



519. A. radicale, P. Beaitv. St. creeping, witli sub- 

 erect, rigid brancbes. L. spreading, ovate-lanceolate, 

 from a cordate or deltoid base, and strongly nerved 

 almost to the long, tapering apex ; per. 1. larger, 

 serrate, seta long (sometimes 2 incbes). Caps, arcuate- 

 cylindric, cernuous, not red at moutb, lid conical, witb 

 a short, sharp beak. 



Moist ground amongst grass. April, May. 



520. A. irriguum, Wils. St. procumbent, rigid, 

 sometimes pinnate. L. spreading, secund, gradually 

 tapering to a point, from a deltoid-ovate, somewhat 

 decurrent base, subserrulate, strongly nerved nearly 

 to apex. Caps, oblong, cernuous, curved, when dry 

 more so, and contracted at mouth, annulus persistent, 

 lid conical, blunt pointed. 



Stones in rivulets and streams. Apfil.' 



521. A. fluviatile, Swartz. St. procumbent, witb 

 simple, prostrate, not rigid branches. L. patent or 

 subsecund, ovate or ovate-lanceolate, decurrent, acute, 

 entire, concave, strongly nerved almost to apex, margin 

 recurved below. Caps, slender, elhptical, elongate, 

 suberect, only slightly curved, lid conical. 



Eocks and stones in mountain streams. May, June. 



ti. Leaves broadly ovate, more or less longly acumi- 

 nate, decurrent at angles, cells thin-walled, long 

 hexagono-rhomboid, laxer at base, at angles rectan- 

 gular. 



522. A. riparium, IJrin. St. long, creeping, with 

 subpinnate, suberect branches. L. spreading, rarely 

 subsecund, subcomplanate, ovate- lanceolate, entire, 

 nerved two-thirds or more. Caps, oblong, cylindrical, 



