286 FRYE 
So named because the leaves are strongly incurved or twisted when 
dry. 
Plants dioicous, loosely czespitose, glaucous green, reddish-brown 
when old. Stems 1—3 cm. high, erect, rigid, simple. 
Leaves erect or spreading, lanceolate from an oblong base, more or | 
less acute; when dry strongly incurved and twisted but less crisped 
and undulate than in Catharinea. Margin not bordered, incurved 
at least above thus making leaves somewhat tubular near tip, 
remotely and minutely dentate at apex but sometimes entire. Lam- 
elles on upper side 1o— 13, wavy from side to side, 6—12 cells high, 
their margins variously notched and crested. Vein with 2—3 
lamelle on back; back lamelle short, blunt, low, serrate, rather ridges 
than lamella, sometimes wanting. Cells hexagonal, rectangular at 
base; cell-walls meeting margin of leaf perpendicularly. 
Calyptra with a few scattered hairs. 
Capsule ovate-cylindric, erect or somewhat inclined, somewhat 
irregularly plicate when dry, contracted below the mouth, with 
numerous stomates. Teeth short, unequal. Lid shortly rostrate, 
oblique, often falling off with the calyptra. Pedicel smooth, rather 
thick, 2—4 cm. long.—On soil.—Rogers Pass, Selkirk Mountain, 
British Columbia; Greenland; Europe. 
COMPARISON OF VARIETY WITH TYPE. 
3. QO. incurvum, typical. 
1. Cells wall in upper half of leaf approaching leaf margin perpendicu- 
larly. 
2. Cells about midway between base and tip .o1o-.o15 mm. in their 
longer diameter. 
3. Leaves usually remotely dentate, but sometimes entire. 
4. Vein usually with 1-3 low serrate ridges or lamelle on back, 
but sometimes smooth. 
5. Capsule somewhat irregularly plicate. 
3a. O. incurvum var. latifolium® (C. M. & Kindb). 
Oligotrichum hercynicum var. latifolium C. M. & Kindb., Mac. Cat. 
VI, p. 149, (1892). 
Oligotrichum integrifolium Kindb., in Revue Bryol. 1894, p. 40. 
6 Name derived from latum = broad, and folium = leaf; referring to the leaves 
being broader than in the type. 
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