Var. pilifera , Muell. Apex of tlie leaves prolonged Into a
flexuous hair. — Bryum piliferum, Dloks. Pl. Crypt. Iv. 10.
Pottia pilifera, Lliidb. Trichost. 223.
Hab . Naked ground iu alpine districts; Colorado (Downie, Wolf,
Bothrock) ; Uinta Mountains ( TFaisoii) ; British America (Drummond).
4 0 . DIDYMODON. Hedw. (Pl. 2.)
Plants repeatedly dichotomous, fastigiate, radiculose at base.
Areolation of the leaves narrower than In the preceding genus,
hyaline at base, chlorophyllose and densely papillose In the
upper part. Flowers polygamous and dioecious, gemmiforrn.
Calyptra long, cucullate. Teeth of the peristome plane,
slender, linear-lanceolate, confluent at base, nearly entire or
spilt either partly or sometimes their whole length, distantly
articulate, punctulate, not papillose, often irregular. Annulus
distinct.
Distinguished from Trichostomum by the peristome composed of a flat
double lamina, and by the softer and more papillose leaves.
1. D. ru b e llu s, Bruch & Schimp. Plants in reddish tnfts,
slender, about two c.m. long : leaves erect at base, open,
flexuous above, crispate when dry, the lower lanceolate, shorter,
the upper linear-lanceolate, acuminate, half-clasping at base,
the borders revolute above, minutely papillose on both faces ;
costa narrow, percurrent ; perichætial leaves with a longer
clasping hyaline very thin base : capsule oblong-oylindrieal, of
thin texture, dusky green when filled ; lid short or long-rostrate,
inclined ; teeth linear, more or less strongly articulate, entire or
perforated along the divisural line, soft, pale red; annulus
large, fragile. — Bryol. Eur. t. 185. Bryum rubellum, Hoffm.
Weisia recunirostris and curvirostris, Auct. Tricliostomum
rubellum, Rabenh. ; Muell. Syn. 1. 581 ; Lindb. Trichost. 226.
Hab . , On stones or on the ground, on or near the water; plains and
mountains; not uncommon on both the eastern and western slopes.
2. D. lu rid u s , Hornsch. Dioecious: tufts green wlien
moist, dirty brown when dry, half to one c.m. long, simple or
sparingly branching; leaves open when moistened, imbricate
when dry, the lower broadly ovate-lanceolate, the up>per longer,
ovate at base, lanceolate above, blunt or acute, concave, with
borders reflexed and surface nearly smooth ; costa stout.
1 0 5
vanishing with or below the apex ; areolation distinct, rectangular,
a little enlarged in the lower part ; perichætial
leaves erect, similar, with a loose areolation : lid conical, acuminate
or blunt, inclined or erect, variable iu length ; teeth
irregular, simple or variously divided, sometimes rudimentary;
basilar membrane none ; annulus very narrow, persistent. —
Spreng. Syst. iv. 173 ; Bryol. Eur. t. 186. Trichostomum
luridum, Spruce ; Lindb. Trichost. 226.
Var. c u sp id a tu s , Schimp. Leaves cuspidate by the ex-
ourrent nerve.
H a b . Niagara Falls (Drummond, Clinton); Minnesota (Lapham);
abundant on limestone rocks washed by spray, northern shores of Kelly
Island, Lake Erie (Lesquereux).
3. D. cy lin d ricu s, Bruch & Schimp. Dioecious: loosely
cespitose, jjale green : leaves long, open, flexuous, linearacuminate,
twisted when dry, whitish at the base, fragile, flat,
opaque-verruculose above, minutely crenulate on the borders,
or with a few distinct teeth near the apex ; costa narrow, ex-
current into a short point: capsule narrowly cylindrical, on a
long pale soft pedicel ; lid long-rostrate, subulate ; teeth narrowly
linear-lanceolate, entire or diversely lacerate-perforate,
fugacious; annulus narrow, persistent. — Bryol. Eur. t. 187.
Weisia cylindrica, Bruch ; Brid. Bryol. Univ. 1. 806. Weisia
tenuirostris. Hook & Tayl. Muso. Brit. (2 ed.) 83, t. 3, Suppl.
Trichostomum tenuirostre, Lindb. Trichost. 225.
H a b . On old wood and twigs, Chester Co., Pennsylvania, and in the
Alleghany, Catskill and White Mountains (James); Ontario, Canada
(Mrs. Boy) ; rarely fertile.
41. LEPTOTRIOHUM, Hampe. (PI. 1.)
Plants slender. Leaves smooth, lanceolate-subulate ; areolation
narrowly rectangular above, looser hexagonal-rectangular
below. Capsule oval or cylindrical, erect, on a long straight
rarely flexuous pedicel. Teeth of the peristome cleft to the base
into two linear articulate segments, erect or a little mclined to
one side, purple. Annulus compound, deciduous.
* Flowers dioecious.
1. L. to rtile , Muell. Plants short : leaves secund or spreading,
lanceolate-subulate ; borders recurved in the middle ; costa
: .J