HYPNUM. 463 



both when wet and when dry, less denticulate above, and with more or less numerous 

 paraphyllia, and is less regularly pinnate. 



The var. stenophyllum in its extreme forms is very marked ; in outline the leaves 

 resemble those of H. Jluitans, but the colour and branching are distinct, the nerve 

 usually stronger, and the habit more robust. 



The green form, which may be looked upon as typical, is rare, and resembles H. 

 Sendtneri, but has the leaves usually plicate when dry. 



1 1 . Hypnum uncinatum Hedw. (Hypnum aduncum L. sec. 



Lindb., non Hedw. ; Amblystegium aduncum Lindb.) 



(lab. LVII. F.). 



Pale green or golden green, very rarely of a deeper colour, 

 never red nor purple. Stems rarely erect, usually procumbent, 

 often interlaced with other mosses, or more robust and tufted, 

 distantly or closely pinnate, rather slender, 1-4 inches long. 

 Leaves more or less crowded, regularly falcate or almost circinate, 

 little altered when dry or in the softer forms spirally flexuose at 

 points, glossy, strongly longitudinally plicate when wet and dry, 

 strongly hooked at the tips of the stems and branches, of thin, 

 not solid texture ; narrowly oblong-lanceolate, gradually tapering 

 to a very fine, filiform acumen, at margin usually denticulate at 

 point and often at base, rarely entire ; at base often broad and 

 flat, with minutely decurrent auricles and hardly excavate, but 

 always more or less decurrent and auriculate ; nerve very 

 narrow, 30-35 ;«. wide at base, extending high in the acumen. 

 Cells very narrow, long, flexuose, somewhat tapering and pointed, 

 thin-walled , almost uniform to base ; angular, more or less 

 numerous, hyaline, but not very large nor inflated, partly 

 decurrent and partly extending above the base at angles, forming 

 rather small, not well-defined auricles. Perichaetial leaves very 

 long, straight, erect, sheathing, plicate ; seta variable in length, 

 capsule sub-cylindric, arcuate, orange-red, annulate. Autoicous. 



Var. /?. plumulosum Schp. Very slender, closely pinnate; 

 leaves small, less deeply striate, less denticulate or sub-entire ; 

 seta shorter, capsule smaller. 



Hab. Wet rocks and walls, principally in alpine and subalpine districts ; 

 common. The var. rare, on mountains ; Snowdon. Fr. summer. 



Usually a very distinct species in the pale colour, thin, strongly plicate, very 

 finely acuminate, denticulate leaves with narrow nerve and small ill-defined auricles 

 which are, however, always more or less developed. Numerous forms occur on the 

 continent, and perhaps still more strongly marked in N. America, but the more 

 distinct of them do not appear to occur here, though the var. plumosum Schp., a 

 somewhat distinct form with regular close complanate pinnation, but connected with 

 the type by a regular series of forms, is found occasionally ; it is intermediate between 

 the type and the var. plumulosum. The latter variety is very distinct, not only in the 



