494 hypnacEjE. 



The regularly and closely bi-tripinnate branching is the most obvious characterof 

 this species, which otherwise has some similarity to Hypnum Schreberi, but is quite 

 different in structural points. The mode of growth is somewhat unusual ; at various 

 points of the stem, and sometimes at its apex, arise strong, bright green erect shoots, 

 usually curved at the tip, with crowded, julaceous leaves and close, short, simple 

 branches atthe summit, being usually unbranched below; these shoots gradually develope 

 into the slender, bipinnate fronds, duller in colour, and gradually becoming more 

 prostrate, characteristic of the older part of the plant ; when these innovations arise 

 laterally, the stem becomes divided, when on the other hand they form a prolongation 

 of the stem, the latter becomes interruptedly bipinnate. These more or less erect, 

 bright green shoots, are often very characteristic and distinct. Slender forms some- 

 times occur among other mosses with more erect, simply pinnate stems, and these 

 "become more difficult to distinguish in the field from Hypnum Schreberi and from 

 Hylocomiiim umbratum. The acuminate stem -leaves and the numerous paraphyllia, 

 -quite visible with the lens, will distinguish it from the first ; while in Hyl. umbratum 

 the branching is more irregularly pinnate, hardly ever at all distinctly complanate, the 

 .stem-leaves shorter and wider and more distinctly striate, and all the leaves more 

 triangular, more crisped when dry and less scariose, the colour usually of a brighter 

 :green, not yellowish brown nor olive. 



The distant, spinulose papilla? on the back of the leaves are often very few, but 

 frequently very numerous and distinct ; on the branch-leaves they are usually reduced 

 to indistinct notches. 



2. Hylocomium umbratum B. & S. (Hypnum umbratum 

 Ehrh.) (Tab. LX. H.). 



Slender, rigid, more erect than H . splendens , more irregularly 

 and less complanately branched, pinnate or bipinnate ; branches 

 unequal, slender, more or less attenuated, frequently drooping, 

 sometimes somewhat interruptedly crowded ; stems reddish, 

 clothed with numerous paraphyllia ; forming loose, deep tufts, 

 3-8 inches high, of a bright or yellowish green, not very glossy. 

 Stem-leaves not densely crowded, sometimes distant, rather 

 spreading, about 1 line long, widely, almost equilaterally 

 triangular, more or less longly acuminate, or only very acutely 

 pointed, decurrent, strongly plicate, somewhat undulate at margin 

 with very strong, unequal, often spreading and recurved teeth all 

 round ; nerve double, reaching about half-way ; cells as in H. 

 splendens, or a little larger and longer, not distinct at angles ; 

 without papillx at the back of the leaf. Branch-leaves smaller, 

 triangular-ovate or widely ovate. Perichaetial bracts squarrose 

 at the points. Capsule rather short, ovate ; lid shortly apiculate. 

 Dioicous. 



Hab. Mountain woods on rocks and earth. Very rare. North of England. 

 Scotland. Fr. very rare, spring. 



The very numerous paraphyllia combined with the slender habit distinguish 

 this species from all but H. splendens ; the branching is never distinctly complanate, 

 nor so regularly bipinnate as in that ; and the leaves are always more distinctly plicate, 

 somewhat undulate and more altered when dry, and more triangular, even the branch- 

 leaves. Eurhynchium pralongum var. Stokesii sometimes resembles it in habit, but 

 the squarrose stem-leaves and narrow branch-leaves alone will distinguish that plant 

 without recourse to the microscope. 



