388 BRYACE^. [Ilypnum. 



Subgenus XX. RHYTIDIUM. 



Plants robust, without radicles, irregularly pinnate-ramulose. 

 Leaves transversely plicate, rugose, costate to the base of the 

 point ; upper areolation linear-vermicular, the lower sinuous, 

 rectangular in the middle, minutely quadrate at the borders 

 and angles. Flowers dioecious. Calyj)tra large, descending to 

 the base of the capsule. Capsule solid. Operculum rostrate. 

 Annulus very broad. 



144. H. rugOSUm, Linn. In wide dirty yellowish or pale 



green tufts; stems arcuate or erect, stout : stem-leaves densely 



crowded, imbricate-secund or erect-spreading on the bi-anchlets, 



lanceolate, narrowly acuminate from a broadly oblong base, 



coi'rugated by numerous short wi'inkles, concave, rellexed on 



the borders, sharply serrate at the apex, gloss}^; inner peri- 



cha'tial leaves deejily sulcate, ecostate, croso, serrate at the 



apex: capsule oblong-cylindrical, much arched, gradually nar-. 



rowed upward and constricted under the orifice when dry; 



pedicel smooth; teeth ferruginous; segments broadly split; 



cilia two, as long as the segments ; annulus of a triple row of 



cells, remaining attached to the oi)ci-culuin. — ]\[nnt. i. 131; 



Bi-yol. Eur. t. CIO. //. rugulosrcm, Web. & Mohr. ILjlocondum 



riigosurn^ DeNot. Briol. Ital. 99. 



Hab. Borders of woods, either dry or wet, not uncommon but gen- 

 erally sterile: found fertile only at Glen Eyrie, Colorado, on a sandy 

 slope, by T. C. Porter. 



145. H. robustum, Hook. Stem creeping; branches very 

 stout, drooping, yellowish green : leaves densely imbricate, ap- 

 prcssed, homomallous, transversely rugose-striate, distinctly 

 plicate lengthwise below, scarious, ovate-lanceolate, long-acu- 

 minate, subserruUite toward the apex, bicostate or rarely simply 

 costate to nenr the middle ; borders revolute ; cells very narrow, 

 the alar scarcely different ; perichretial leaves whitish, reflexed, 

 loosely reticulate at base: ca]>sule oblong-cylindrical, cernnous; 

 pedicel purple; operculum conical, obtuse, mamillate. — Muse. 

 Exot. t. 108 ; Schwaegr. Snppl. iii. t. 261 ; Muell. Syn. ii. 256. 

 Stereodon rohustus, Mitt. Journ. Linn. Soc. viii. 41. 



Hat?. Northwestern coast (Menzies):, Oregon (Molir)\ Fort Colville 

 (Lyall)', Rocky Mountains of British America (Drummond); North- 

 western Montana ( Watson). 



