410 MUSCI. Hypnum. 



5t. HYPNUM, Dill. 



Variable in habit and mode of growth ; primary stetn prostrate, the secondary 

 stems irregularly and subfasciculately branched or more or less regularly once or 

 twice pinnate. Leaves iv.ther broad, mostly smooth and shining and more or less 

 scarious, costa short or wanting or rarely percurrent ; areolation mostly narrowly 

 prosenchymatous, linear or flexuous-linear, rarely rhombic or hexagonal. Inflores- 

 cence various (more frequently dioecious), lateral, bud-like. Calyptra dimidiate, 

 smooth. Capsule long-pedicellate, more or less cernuous and unsymmetrical ; oper- 

 culum conic or rostrate. Peristome double as in the preceding genera, the inner 

 upon a broader basal membrane (about half the length of the teeth), with cilioLe. 



A large and difficult genus of over 500 species, which is readily divisible into several more or 

 less well-marked groups. Schimper proposes 20 or more genera for the European species, half of 

 which are represented in the Californian flora, but it will be most convenient here to consider 

 them only as subgeuera or sections. The species are often of difficult definition and based upon 

 apparently slight characters. 



1. Ramification pinnate (excepting n. 4) : leaves papillose, acuminate, costate 

 to the apex, equally spreading: operculum conic. 



* Pedicel scabrous or tubercuLate : flowers dioecious. 



1. H. Whippleanum, Sulliv. Stems filiform, 1 or 2 inches long, pinnately 

 twice or thrice divided, arcuately prostrate, radiculose at the top, the numerous 

 branchlets 3 to 5 lines long : leaves erect-spreading, ovate-lanceolate, papillose on 

 the back, entire margin serrate, pellucid, costa reaching nearly to the apex, areolation 

 quadrate oblong : capsule on a tuberculate pedicel 5 to 7 lines long, abruptly hori- 

 zontal, oval or oblong, somewhat unequal, dark chestnut with blackish distinct 

 obtuse collum ; operculum constricted in the middle ; annulus none : ciliolse in 

 pairs, equalling the processes and whitish teeth. Pacif. R. Rep. iv. 190, t. 9; 

 Sulliv. & Lesq. Muse. Am.-Bor. Exsicc. 2 ed. n. 407. 



On the ground in mountain canons near the Bay of San Francisco, Bigelow. 



2. H. crispifolium, Hook. Stems 4 or 5 inches long, branches slightly in- 

 curved, simply pinnate with short unequal branchlets : leaves crowded, bright green, 

 erect-spreading, crisped when dry, lanceolate from a broadly cordate subdecurrent 

 base, serrate, flexuose, narrowly long-acuminate or sometimes tipped with a hyaline 

 hair, the pale costa ceasing below the apex, verv finely papillose, areolation minute, 

 rounded ; perichsetial leaves smooth with a very long and narrow denticulate acurni- 

 nation : pedicel short, very scabrous, purple : capsule horizontal, pale, incurved- 

 oblong, broadly annulate ; operculum obliquely beaked : processes broadly gaping 

 or divided ; ciliola? 2 or 3, nearly as long. Muse. Exot. t. 31 ; Lesq. in Trans. 

 Amer. Phil. Soc. xiii. 11 ; Sulliv. & Lesq. 1. c., n. 405. H. ramulosum, Hampe ; 

 Muell. Syn. ii. 486. 



On shaded ground and rocks, near Oakland, and near Paper Mill, Marin County (Bolander) ; 

 Oregon (Nevius) ; Vancouver Island, Menzies, Wood. 



H. LAXIFOLIUM, Schwaegr. Suppl. t. 143 (Leskea laxifolia, Hook. Muse. Exot. t. 30), collected 

 by Menzies and not since identified, appears to be a similar species, but with broader and less 

 attenuate leaves, a shorter and more turgid capsule, the processes less dehiscent, and the ciliolae 

 very short and imperfect. 



* * Pedicel smooth. 



3. H. calyptratum, Sulliv. Very small ; stem filiform, subsimply pinnate, 

 flagelliform at the summit : leaves erect-spreading, broadly ovate, narrowly long- 

 acuminate, denticulate, costate to the apex, sparingly papillose on the back, areolation 

 minute and subquadrate : flowers monoecious : calyptra very long, embracing the 

 pedicel : capsule cylindric, oblique, curved ; operculum obtuse ; annulus none : 



