HYLOCOMIUM. 499 



long, flexuose, simple or with few, short, more or less regularly 

 pinnate branches ; 2-4 inches long. Stems and branches very 

 tumid and robust with the large, closely imbricated, concave 

 leaves ; forming large, glossy, yellowish green or golden brown 

 tufts. Leaves if-2 lines long, widely oblong-lanceolate or ovate- 

 acuminate, rather rapidly tapering to a moderately long, acute, 

 "flexuose acumen, regularly falcato-secund but not circinate nor 

 very strongly curved, except at the tips of the branches, which 

 are slightly hooked ; somewhat membranaceous in texture, 

 longitudinally plicate and strongly transversely undulate-rugose 

 both when wet and when dry, narrowly revolute at margin for 

 the greater part of its length, more or less strongly denticulate, 

 at back studded with more or less numerous but not crowded, 

 .stout, acute, spinulose papillse, pointing forward ; nerve single, 

 often slightly forked, very slender in the upper part, reaching 

 half or two-thirds the length of the leaf. Cells short, 5-8 times 

 as long as wide, linear, obtuse, flexuose, incrassate, almost 

 uniform to mid-base ; angular very numerous, small, irregularly 

 quadrate-rounded, sub-equal, very distinct, but opaque and 

 granulose, forming distinct angular bands reaching high at 

 margin but not wide. Dioicous. 



Hab. Among grass, etc., on rocks, preferring those which are calcareous; 

 principally on mountains. Not common. Fruit not found in Britain. 



A very distinct and not very variable plant, somewhat resembling Hypnum 

 lycopodioides in habit, but of quite different structure, and found in quite distinct 

 habitats, with the undulations not large and irregular as in that, where they are 

 merely the result of drying, but small, strong, and more regularly transverse, almost 

 as marked in the moist state as when dry. The spinulose papilla? at back are often 

 very numerous and striking. Schimper places it in the sub-genus Rhytidium of 

 Hypnum, but it appears to be as much at home in the present genus as in Hypnum, 

 and in some respects, especially in the papillose leaves, more so. 



