POLYTRICHUM. 41 



crowded, fasciculate branches ; glaucous green, brown below. 

 Lower leaves scale-like, apiculate, upper lanceolate from a pale 

 sheathing base, patulous when moist; rigid, appressed to stem, 

 erect or slightly incurved when dry ; crowded, long, at apex acumi- 

 nate to an acute point formed by the slightly excurrent nerve, 

 which is sharply spinose at back. Limb plane, sharply toothed at 

 margin from near the base ; areolation of the base narrowly 

 rectangular, without chlorophyll, whitish brown, of the limb quad- 

 rate-hexagonal or rounded, at base of limb very narrowly trans- 

 versely elliptical, small and dense. Lamellae about 50, low, very 

 much crowded, in section of 4-6 cells, the uppermost larger, 

 rounded, yellowish brown, papillose, the rest smaller, green. 

 Seta rather long, \-\\ inches, slender, pale reddish. Calyptra 

 longer than capsule. Capsule erect or very slightly inclined, 

 symmetrical , resembling the last but larger and somewhat more 

 cylindrical, wide-mouthed, golden brown, finally brown, very 

 papillose, without stomata. Teeth of peristome reddish. 



Var. fi. humile Wahl. (Pog. urnigerum var. humile Brid.). 

 Stems short, simple, scattered ; leaves shorter. Capsule narrower 

 and smaller, on a shorter seta. 



Hab. Dry and stony places ; most common in subalpine situations ; the var. £ 

 in drier, more exposed situations, more rare. Fr. autumn and winter. 



The var. humile is perhaps rather a starved form than a permanent variety. The 

 glaucous colour will usually distinguish the present from the next species, as also the 

 erect, symmetrical, papillose capsule. 



P. capillare Rich., found in Scandinavia, and common in N. America, is some- 

 what intermediate between this and P. aloides ; with the habit of the latter it has 

 very sharply serrate leaves, the teeth being often patent and recurved. The European 

 form (Schf. Syn. Ed. 2, p. 336) is, however, not so strongly marked. 



4. Polytrichum alpinum L. (Pogonatum alpinum Rohl, 

 Schp. Syn.) (Tab. X. B.) 



Stems loosely tufted, tall, much branched, decumbent at base. 

 Leaves dull green, rather longer and more flexuose than in the 

 last species, more narrowly acuminate, the serratures slightly less 

 acute in outline ; lamellae fewer, about 35, less crowded, higher, 

 in section of 5-6? cells, the marginal ones larger, ovate-conical, 

 papillose, yellowish. Seta long, flexuose. Capsule inclined and 

 arcuate, variable in size and form from sub-globose to elongate- 

 cylindrical and curved, usually oblong-cylindrical, and somewhat 

 gibbous on the upper side, narrower at the mouth than below, not 

 papillose, with a short neck, bearing stomata, greenish brown, 

 blackish when old and rugose ; lid with a rather long subulate 



