HYLOCOMIUM. 497 



6. Hylocomium squarrosum B. &S. (Hypnumsquarrosum~L.) 



(Tab. LX. J.). 



Stems more or less erect, without parapbyllia, usually 

 prostrate at base and then ascending or erect, tall, 4-6 inches, 

 more slender and flexuose than in H. loreum and H . triquetrum, 

 forming dense pale green or yellowish green soft tufts, whitish 

 below, glossy. Leaves more or less crowded, i£ lines long, from 

 an erect, sheathing, cordate-ovate base suddenly recurved- 

 squarrose, in a long, gradually tapering, linear-lanceolate, 

 channelled acumen, imbricated all round the stem, not secund ; 

 at apex of stems stellately spreading so as to render the stems 

 very obtuse ; not plicate, or very lightly so at base only ; finely 

 denticulate, especially above ; nerve short and faint, double, 

 hardly reaching half way; cells rather larger than in the 

 preceding species of the genus, 8-10 times as long as wide, 

 smooth at back ; angular wider, short, rectangular-hexagonal, 

 opaque or pellucid, often orange, very numerous, forming large, 

 distinct but not well-defined auricular patches extending con- 

 siderably towards the nerve. Branch-leaves smaller, narrower, 

 less squarrose. Seta slender, \-\\ inches long, capsule short, 

 turgidly oval, gibbous at back ; lid acutely conical. 



Var. /3. calvescens Hobkirk (Hypnum calvescens Wils. ; Hyl. 

 calvescens Lindb.; Hyl.squarrosumvax. subpinnatum Schp. ,Syn.). 

 Stem-leaves usually wider at the base, cordate-triangular rather 

 than cordate-ovate ; generally but not always somewhat distinctly 

 plicate below when dry, more shortly acuminate, more strongly 

 denticulate above, the auricles more clearly defined and pellucid ; 

 stems more closely pinnate, with robust or more slender, 

 attenuated, flexuose branches ; branch-leaves very distinct from 

 the stem-leaves, widely ovate, very shortly acuminate or only 

 acute, not squarrose, half twisted when dry. 



Hab. Grassy banks, hedgerows, etc., abundant. Fruit rare, winter and spring. 



A very common species, known at once by its pale colour, tall, somewhat soft and 

 slender stems, and strongly recurved-squarrose leaves ; the acumen of which spreads 

 in different ways, sometimes about horizontally but often so strongly reflexed as to be 

 parallel with the stem and to touch the leaf immediately below it. The more strongly 

 reflexed rather than recurved leaves, not falcato-secund, not or hardly striate, and the 

 much more slender and softer habit of the plant abundantly separate it from S. loreum ; 

 while H. triquetrum is still more distinct in its straight, not reflexed nor recurved 

 leaves, scabrous at back, and by its much more robust, stiff habit. 



An almost prostrate form is not unfrequently found by roadsides and on the beds 

 of dried up pools. 



The var. calvescens is a very curious and distinct form, when typical ; it bears a 

 great resemblance in its strongly marked forms to Hyl. brevirostre, but the smooth 

 stems without paraphyllia at once separate it. It appears to me clear that it can only 

 GI 



