MOSS HABITATS. 35 



with earthy deposits, dull deep green in colour, and will be 

 recognised by the lance-shaped, blunt, keeled leaves, having 

 a strong nerve scarcely reaching the leaf tip. The fruit- 

 stalk is terminal, the capsule erect and egg-shaped, peristome 

 of sixteen teeth, lid conical with an oblique beak, fruiting in 

 November. Bartramia calcarea may be found in wet places 

 in calcareous or marly soils, and has somewhat the appear- 

 ance of B. fontana, from which it may be known by the 

 intense and beautiful green colour of its leaves. The leaves 

 are more rigid, destitute of border, with larger cells ; and 

 the leaves of the male flower are acute and nerved to the 

 apex, those of B. fontana being obtuse and nerveless. 

 , A, .moss-grown tree is always an attractive object to me, 

 ancf many a pleasant hour has been spent looking over these 

 mossy invaders in search of some rare or local species. The 

 trees most prolific in moss tenants in Warwickshire (better 

 known to me than any other county) are the ash, elm, lime, 

 Ontario poplar, sycamore, and apple. The oak is often 

 moss-grown, but not to the extent of the above-mentioned, 

 nor are its inhabitants so truly tree-loving species. On the 

 beech and the coniferae I rarely find mosses. In other 

 climates these also have their special tenants. The mosses 

 which I should designate tree-loving mosses are such as the 

 Orthotrichums r Cryphaa,Leucodon sciuroides^Zygodon^ Weissia 

 drrhata, Leskea polycarpa, etc. 



The prthotrichums are very distinct-looking mosses, oc- 

 curring in larger or smaller tufts. The fruit-stalks are very 

 short and usually hidden by the surrounding leaves. The 

 capsules, with one exception, are striated or streaked "(fig. 

 20, 2), and always erect, the calyptra bell-shaped (fig. 20), 

 longitudinally plaited, and more or less covered with erect 

 hairs, the leaves in most cases erect when dry, and more or 

 less covered with minute papillae, and the leaf- margin in 

 most cases turned over towards the under-surface or revo- 

 lute, leaf-cells roundish. If the above characters are borne 

 in mind they will be great helps. 



Orthotrichum affine will be found frequently on the ash, 

 elm, and poplar, in large, loose, dark-green tufts, a rather 

 coarse-looking moss, with a pale, yellowish-green calyptra. 



