HYPNUM. 489 



procumbent, with erect divisions which are long, almost simple or 

 distantly and very irregularly pinnate, cuspidate at the tips ; 

 forming deep, soft tufts of a bright or yellowish green. Leaves 

 distant, erecto-patent or spreading, soft in texture and somewhat 

 shrinking when dry; large, i-if lines long, wide, cordate-oval or 

 ovate-oblong, rounded and contracted to a longly decurrent inser- 

 tion, slightly concave, rounded-obtuse and often cucullate at 

 summit, entire, not plicate ; nerve single, reaching nearly to apex, 

 slender, but distinct; cells large, 130-160 /x long, 8-10 fi wide, 

 linear-sub-hexagonal, pointed, thin-walled, a few at apex short and 

 wide ; gradually wider towards base, all basal large, wide, more 

 ■or less pellucid, hexagonal or rectangular, forming wide, decurrent 

 bands reaching to the nerve, not well-defined auricles. Seta 2-3 

 inches long, flexuose. Capsule rather large and turgid, oblong, 

 ■curved. Autoicous. 



Hab. Marshes and pools, not common. Fr. rare, summer. 



Somewhat variable in size and robustness, its slender forms coming near in 

 appearance to forms of H. cuspidatum and of H. riparium, but quite distinct from 

 the latter in the obtuse leaves, from the former in the more distant, single-nerved 

 leaves. H. giganteum differs in the numerous, crowded branches, the colour usually 

 deeper and more lurid, and the narrower areolation, with the auricles very distinct. 



A continental and N. American species, H. Richardsoni Mitt. ( H. Breidkri 

 Juratz.) is somewhat intermediate between these two species, but certainly, judging 

 from the specimens I have seen, nearer to H. giganteum, having the auricles distinctly 

 defined, the habit more robust and the colour deeper, though the branching is some- 

 what more that of H. cordifolium and the inflorescence autoicous. 



37. Hypnum giganteum Schp. (Amblystegium giganteum 

 DeNot.) (Tab. LIX. M.). 



Allied to H . cordifolium ; more robust, with very close, 

 numerous, pinnate, not complanate branches, which are irregular 

 in length, obtuse or cuspidate, usually with very narrow leaves ; 

 in dense tufts of a dark, lurid green, often tinged with yellow or 

 red. Stem-leaves large, more rigid and glossy when dry, resembl- 

 ing those of H. cordifolium but rather larger, more densely 

 crowded ; cells smaller, narrower , linear-flexuose, less enlarged 

 towards base ; at extreme base suddenly enlarged, hyaline, 

 inflated, forming large, well-defined, decurrent auricles extend- 

 ing almost to the nerve. Dioicous. 



Hab. In similar situations with the last ; not common. Fr. very rare, summer. 



The very dense, pinnate branching gives the plants a very robust and bushy 

 appearance, quite distinct from that usual in H. cordifolium ; somewhat slender and 

 less branched forms occur, however, and then the well-defined auricles and narrower 

 upper cells are the best identifying points. The difference of areolation does not 



