187 
18. BRACHYTHECIUM PLUMOSUM (Sw.) Br. & Sch. Bryol. Eur. 
fasc. 52-54. pl. 537. 1853. 
Hypnum plumosum Sw. Disp. Musc. Suec. 66. 1799. Not 
Huds. or Hedw. 
Hypnum pseudo-plumosum Brid. Musc. Rec. 2: 108. 180r. 
Hypnum flagellare Hedw. Sp. Musc. 282. pl. 73, f. 1-3. 
1801. (Fide Limpricht). Not Dicks. 
Hypnum chrysostomum Mx. Fl. Bor. Am. 2: 319. 1803. 
(fide Limpricht). 
Brachythecium rutabuliforme Kindb. Macoun, Cat. Can. Pl. 6: 
Gametophyte robust, in wide loosely-intricate mats, brownish- 
green to golden-green, usually glossy on the surface, brown 
underneath ; stems 3-6 cm. long, creeping, pinnately branching, 
clinging closely to the substratum at the borders of the mats ; 
branches ascending or erect, straight or somewhat curved, 
5-10 mm long; branch leaves equally spreading or somewhat 
secund, rather loosely erect-spreading, lanceolate to broadly 
ovate-lanceolate, long-acuminate, 1.1—1.5 X 0.4—0.5 mm., entire or 
serrulate near apex, more or less concave, decurrent ; costa extend- 
ing 24 the length of the leaf; median cells linear, 8-12:1; a 
few basal cells broader and shorter; quadrate alar cells few ; 
stem leaves narrowly triangular-ovate to broadly ovate, acuminate, 
more loosely areolate, nearly entire: monoicous ; male branches 
abundant; antheridia oblong ; inner perigonial leaves ovate-acum- 
inate, bordered by a row of narrow cells, generally costate: peri- 
chaetium 1.5—2 mm. long ; leaves sheathing with spreading points, 
oblong-ovate to oblong-lanceolate, rather abruptly narrowed to a 
long slender acumination, nearly entire, more or less distinctly 
costate. Sporophyte 7-20 mm. high; seta dark red-brown to 
almost black, rough above, nearly smooth below; capsule chest- 
nut brown, black when old, oblong-ovoid, 2.2-2.5 mm. long, 
2.5:1, horizontal to suberect, nearly symmetric or slightly 
curved, slightly contracted under the mouth when dry ; operculum 
conic, almost rostrate ; annulus narrow, of a single row of cells ; 
cilia 2 or 3, well developed, appendiculate ; spores nearly smooth, 
13-16y, maturing in late autumn. 
