BARTRAMIA. 289 



indistinct in the limb, excurrent in a fine denticulate subula ; 

 basal cells hyaline, very long and narrow, 4-10 times as long as 

 broad, linear; in the limb shorter, 3-6 times as long as broad, 

 opaque and obscure, sharply papillose. Capsule as in B. pomi- 

 formis, on a usually rather longer seta. Synoicous. 



Hab. Clefts of mountain rocks, frequent. Fr. summer. 



Superficially resembling B. pomiformis this species is really very distinct, and may 

 be distinguished from it in the field by the sheathing leaf-bases, which by their white, 

 shining surface and erect, sheathing position, give a very distinct appearance to the 

 stem. In the former plant the leaf base although sometimes white and shining is 

 never so distinctly so as in the present species, nor is it sheathing nor so clearly 

 differentiated from the limb of the leaf. The more rigid position of the leaf when 

 dry is not a reliable character, for I have plants of B. pomiformis and of B. ithyphylla 

 in which this relation is exactly reversed. 



The nerve is usually said to occupy the greater part of the width of the limb, but 

 if the leaf be treated so as to render it more translucent it will be seen that the nerve 

 is really comparatively narrow and that the lamina continues wide until very near the 

 apex. The areolation is quite distinct from that of B. pomiformis or indeed of any 

 of the species ; that of B. stricta, which most resembles it, being smaller, shorter and 

 more distinct. 



4. Bartramia pomiformis Hedw. (Bryum pomiforme L.) 



(Tab. XL. F.). 



Loosely or densely tufted, soft, yellowish green or pale bright 

 glaucous green, less often dark green, tomentose below, very 

 variable in height (1-3 inches) and other characters. Leaves 

 long (2-2%, lines) , patent, somewhat flexuose, usually stellately 

 spreading when seen from above, generally crowded ; when dry 

 more erect, somewhat crisped ; very narrowly linear-subulate from 

 a paler, hardly expanded and not sheathing base; margin 

 narrowly recurved for nearly the whole length of the leaf, or 

 slightly thickened above, sharply serrate for most of its length in 

 two rows, both on the actual margin and at the folded edge ; nerve 

 rather narrow, excurrent in a spinose-denticulate subula ; cells 

 above papillose, short, elliptical or subquadrate-rounded, at 

 base elongated, linear, hyaline. Seta about f an inch long, erect ; 

 capsule much exserted, cernuous, about 1 line in diameter, deeply 

 sulcate. Autoicous or synoicous ; male flower just below, and 

 hardly separated from the fertile flower. 



Var. /?. crispa B. & S. (Bartramia crispa Sw.). Taller, in 

 looser tufts ; leaves less crowded, longer, more curled when dry, 

 the base more distinct, the innovations of the year often over- 

 topping the ripe fruit. 



Hab. Sandy banks and clefts of rocks, common. The var. on shady rocks on 

 mountains, less frequent. Fr. spring. 

 T 



