Jennings: Manual of Mosses — 8. Orthotrichaceae 101 



stem mostly with no central strand, erect to ascending, or creeping with erect 

 or ascending branches, radicuiose below, or along the creeping stem, with 

 reddish or brownish filam.ents; leaves spreading to squarrose, carinate, mostly 

 from a decurrent base more or less lanceolate, sometimes oblong-lingulate to 

 linear, mostly entire, usually papillose both sides; costa strong, sometimes 

 excurrent-aristate or piliferous; upper cells generally rich in chlorophyll, round- 

 quadrate to round-hexagonal, basal mostly elongate rectangular to linear, pellu- 

 cid; perichaetial usually more or less sheathing: seta erect; capsule erect, sym- 

 metric, collum distinct, oval to pyriform or cylindric, smooth or striate, deeply 

 plicate when dry and erripty; annulus persistent; peristome mostly double, 

 rarely none; teeth 16 united or approximate in 8 pairs, lanceolate, flat, whitish 

 to yellowish or reddish, reflexed when dry, exteriorly papillose or transversely, 

 obliquely, or longitudinally striate, rarely smooth, rather delicately trabeculate; 

 inner peristome of 8 or 16, filiform, or lanceolate; glabrous or papillose seg- 

 ments alternating with the teeth; spores small to very large; operculum long- 

 rostrate; calyptra cucullate and sometimes smooth to campanulate, often plicate 

 and hairy. 



A rather large family of mostly tree-inhabiting species, mostly of tem- 

 perate 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; leaves crispate when dry 1. Amphidium 



B. Stem creeping with erect or ascending branches: peristome single 2. Drummondia 



C. Leaves when dry crispate, at the base ovate and mostly with a hyaline border; cap- 

 sule exserted in our species 4. Ulota 



C. Leaves not ovate at the base nor with hyaline border: capsule immersed or emergent 



in our species 3. Orthotrichum 



1. Amphidium (Nees) Schimper 



{Amphoridium Schimper; ^ygodon Authors) 



Autoicous or dioicous: tufts cushion-like, soft, often extensive, yellowish 

 olive-green to blackish, inside rusty brown: stem furcately 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, rectangular, 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 ex- 

 serted, mostly erect, pyriform, with 8 projecting, reddish-brown ribs, when 

 empty much widened at the mouth and urceolate; annulus none; peristome 

 none; operculum obliquely rostrate froin a low-conic base; calyptra cucullate, 

 glabrous, not plicate. 



A world-wide genus of 12 species, on mainly non-calcareous rocks; 5 species 

 in North America; 2 in our range. 



