I — 
Plate X 
Rhacomitrium canescens ericoides. (i) Plant, Xi. (2) Capsule, X23. (3) Peristome-tooth, 
cleft, X80. (4) Cross section of leaf-margin just below hyaline tip, X400. 
11. Rhacomitrium lanuginosum (Ehrh.) Brid. Mant. p. 79. 1819. [R. 
hypnoides Lindb.] 
Plants green to grayish green. Stems up to 20 cm. long; short tuft-like 
lateral branches many, or else these elongated so there are many elongated 
branches. Leaves lanceolate, up to 5 mm. long, often secund, loosely appressed 
when dry, recurved when moist, hyaline pointed; hyaline point long, papillose 
on both surfaces, erose; margin only 1 cell thick throughout. Green cells of 
the leaf-tip 3-8 times as long as wide except the isodiametric marginal row, 
those near the hyaline cells papillose, the others merely sunken over the cell 
cavity; cells of the leaf-middle 4-8 times as long as wide, of the leaf-base 6-10 
times as long as wide. Dioicous. Calyptra somewhat rough at beak. Seta 
3-7 mm. long, rough toward the base, twisted to the left. Capsule ovate, its 
body about 1.5 mm. long, smooth; annulus of 4-5 rows of cells; lid about 1 mm. 
long, straight, red. Peristome-teeth split almost to base, up to .9 mm long, 
very papillose, not swollen at the joints. Spores 9-1 2/x . — Alaska and Yukon 
to Oregon and Idaho. 
12. Rhacomitrium microcarpum (Schrad.) Brid. Mant. p. 79 (in part), 
1819. [R. ramulosum Lindb.; R. heterostichum microcarpum Boul.] 
Plants light-green to blackish-green or brownish. Stems up to 5 cm. high; 
elongated branches few, short tuft-like lateral branches many. Leaves loosely 
appressed when dry, divergent or somewhat recurved when moist, lanceolate; 
hyaline point present on nearly all leaves, short or long; margin only 1 cell thick 
throughout. Cells convex on the leaf-surface, more so on the upper side; green 
cells near the hyaline tip 2-5 times as long as wide, gradually longer toward 
the leaf-base; modified alar cells often 1-2 rows, hyaline, square or short-rect- 
angular. Dioicous. Calyptra somewhat rough at tip. Seta 4-5 mm. long, 
twisted to the right. Capsule cylindric, its body 1.8-2. 1 mm. long, yellowish 
to brownish; lid with somewhat diagonal beak, almost half as long as the cap- 
sule-body. Peristome-teeth up to .6 mm. long, finely papillose, yellowish-red, 
