Ptychomitrium. MUSCI. 381 



toothed at top, costa ceasing below the apex : capsule brown, with short colliim 

 and small mouth : teeth bifid nearly to the base, the unequal subulate divisions 

 conniveut when dry. Bruch& Schimp. 1. c., t. 262 ; Wilson, 1. c., t. 19 ; Berkeley, 

 Brit. Moss. t. 21, fig. 3. 



On granite rocks above the Yosemite Valley (Bolander) ; in the Alleghany Mountains, and 

 mountains of Europe. 



2. R. depressum, Lesq. Broadly cespitose, depressed, yellowish brown, the 

 loosely leafy steins 4 or 5 inches long : leaves secund, erect, appressed when dry, 

 lanceolate from a broadly ovate semi-auriculate decurrent base, obtuse, usually irregu- 

 larly denticulate at the apex : capsule immersed upon a short pedicel, nearly cylin- 

 drical, with a short collum : teeth irregularly 3-parted or rarely bifid, the divisions 

 distinct or more or less coherent. Mem. Calif. Acad. i. 14. 



Yosemite Falls, Bolander. 



R. NEVII (Grimmia Nevii, Muell. Flora, xxxi. 483, and Torr. Bot. Bulletin, v. 6) is found 

 at Portland, Oregon, Nevius. Dark green or blackish, the stems somewhat naked below : upper 

 branchlets incurved, leafy : leaves appressed-imbricate or slightly spreading, broadly ligulate, 

 obtuse, sparingly erose-denticulate at the apex, very concave, the inner perichsetial nerveless : 

 capsule oval on a very short curved pedicel : segments of the stout red teeth coherent. 



3. Plants ivith more or less numerous short leafy lateral branchlets : leaves 

 diaphanous at the apex (in our species) and setose-tipped: areolation, 

 calyptra and operculum as in 2 : capsule erect : teeth divided into two 

 loncj narrowly lanceolate or filiform segments. RHACOMITRIUM proper. 



3. R. canescens, Bridel. Stems 2 to 4 inches long, erect, the many branches 

 more or less fascicled, yellowish green or hoary : leaves spreading and recurved, 

 the upper often secund, narrowly lanceolate from an oblong base, attenuate into a 

 long white denticulate point, deeply cariuate, minutely papillose throughout, the 

 entire margin recurved : capsule on a long purple pedicel, ovate-conical with a 

 narrow mouth, brown, obscurely striate when dry : operculum equalling or exceed- 

 ing the capsule : teeth very long, filiform, erect, deep purple. Bruch & Schimp. 

 1. c., t. 270, 271 ; Wilson, 1. c., t. 19 ; Fl. Dan. xv, t. 2561, fig. 1. 



Shaded rocks near Paper Mill, Marin County, a variety with pellucid leaves, scarcely papillose, 

 and areolation narrower (Bolander) ; Mount Ranier (Pickering) ; Vancouver Island (Lyall) ; 

 White Mountains, N. Hampshire ; throughout Europe. A variable species. 



R. HETEROSTICHUM, Brid., collected at Fort Colville (Lyall) and in Oregon (Nevius), has 

 shorter stems (^ to 1^ inches long) sparingly branched, the elliptic- or obovate-cylindric capsule 

 smooth when dry and exceeding the operculum, and the short teeth unequally and irregularly 

 divided, incurved when dry. Bruch & Schimp. 1. c., t. 265 ; Wilson, 1. c. Trichostomum hctero- 

 stichum, Hedw. Muse. Frond, ii, t. 25. Also in Colorado (Hall) and Alaska, and European. 



R. LANUGINOSUM, Brid., from Vancouver Island (Wood) and Mount Ranier (Pickering), has 

 its stems much elongated (4 to 12 inches), slender, fragile and much branched, with crowded 

 linear-lanceolate dentate leaves : pedicels short, roughish : operculum as long as the small ovate 

 smooth capsule : teeth very long, filiform. Bruch & Schimp. 1. c., t. 269 ; Wilson, 1. c. ; Fl. 

 Dan. xv, t. 2561, fig. 2. Trichostomum lanuginosum, Hedw. 1. c. iii, t. 2. In the White 

 Mountains and Europe. 



R. MICROCARPITM, Brid. ; Oregon, Hall. Habit of A', canescens, the stems fascicled, with 

 numerous short branches : leaves crowded, recurved, lanceolate with a short white dentate point 

 and the areolation throughout elongated and sinuous : capsule small and thin, cylindrical, pale, 

 twice longer than the conic operculum. Bruch & Schimp. 1. c., t. 268 ; Wilson, 1. c., t. 61. In 

 the White Mountains and the Alleghanies and in Europe. Growing in dry places and maturing 

 its fruit in autumn, not in the spring as the preceding species. 



24. PTYCHOMITRIUM, Bruch & Schimp. 



Perennials, loosely cespitose on rocks or rarely trees. Leaves dull, in 5 to 8 

 ranks, long-lanceolate, crisped, costate, the areolation at the apex minute and puncti- 

 form, at base short-linear or rectangular ; perichaetial leaves not distinct. Flowers 

 nionoacious, bud-like, the male terminal or axillary. Calyptra mitriform, reaching 



