114 A MANUAL OF MOSSES 



gate-rectangular to linear, pellucid ; perichsetial usually more or 

 less sheathing: seta erect; capsule erect, symmetric, collum 

 distinct, oval to pyriform or cylindric, smooth or striate, deep- 

 ly plicate when dry and empty; annulus persistent; peristome 

 mostly double, rarely none ; teeth 16 united or approximate in 

 8 pairs, lanceolate, flat, whitish to yellowish or reddish, re- 

 flexed when dry, exteriorly papillose or transversely, oblique- 

 ly, or longitudinally striate, rarely smooth, rather delicately 

 trabeculate ; inner peristome of 8 or 16, filiform, or lanceolate, 

 glabrous or papillose segments alternating with the teeth; 

 spores small to very large; operculum long-rostrate; calyptra 

 cucullate and usually smooth to campanulate, often plicate 

 and hairy. 



A rather large family of mostly tree-inhabiting species, 

 mostly of temperate regions. 



Key to the Genera. 



a. Calyptra cucullate. not plicate; stems erect or creeping. 



b. 

 a. Calyptra mostly campanulate, plicate; stems mostly erect. 



c. 

 b. Stem erect: peristome none, i. Amphidium. 



b. Stem creeping witli erect or ascending brandies: peristome 

 single. 2. Dnimmondia. 



c. Leaves when dry crispate, at the base ovate and mostly with a 

 hyaline border: capsule exserted in our species. 



4. Ulota. 

 c. Leaves not crisped when dry, not ovate at the base nor with 

 hyaline border: capsule immersed or emergent in our species. 



3. Orthotrichum. 



I. AMPHIDIUM (Nees) Schimper. 



{Amphoridium Schimper; Zygodon Authors). 



Autoicous or dioicous : tufts cushion-like, soft, often ex- 

 tensive, yellowish olive-green to blackish, inside rusty brown : 

 stem fnrcately branching, uniformly foliate, radiculose to the 

 apex with smooth filaments ; leaves linear-lanceolate, papillose 

 both sides, when dry contorted or crispate; costa practically 

 complete, with median guides ; leaf-cells thick-walled, angular 

 to roundish, green, towards the base generally elongate, rec- 

 tangular, thin-walled to hyaline; perichaetial leaves erect, 

 longer, sheathing or half-sheathing: seta short, generally erect, 

 thickening above and grading into the long collum ; capsule 

 emergent to exserted, mostly erect, pyriform, with 8 project- 

 ing, reddish-brown ribs, when empty much widened at the 

 mouth and urceolate ; annulus none ; peristome none ; opercu- 

 lum obliquely rostrate from a low-conic base ; calyptra cucul- 

 late, glabrous, not plicate. 



A world-wide genus of 16 species, on mainly non-calcare- 

 ous rocks ; 7 species in North America ; 2 in our range. 



