I
SüBGENTis XX. RHYTIDIUM.
Plants robust, without radicles, irregularly pinnate-ramulose.
Leaves transversely plicate, rugose, costate to the base of the
point; upper areolation linear-vermicular, the lower sinuous,
rectangular in the middle, minutely quadrate at the borders
and angles. Flowers dioecious. Calyptra large, descending to
the base of the capsule. Capsule solid. Operculum rostrate.
Annulus very broad.
144. H. ru gosum, Linn. In wide dirty yellowish or pale
green tufts ; sterns arcuate or erect, stout : stem-leaves densely
crowded, imbricate-secund or erect-spreading on the branchlets,
lanceolate, narrowly acuminate from a broadly oblong base,
corrugated by mimerous short wrinkles, concave, reflexed on
the borders, sUai'pIy serrate at the apex, glossy; inner perichætial
leaves deejily sulcate, ecostate, erose, serrate at the
apex ; capsule obloiig-cjdindrical, much arched, gradually narrowed
upward and constricted under the orifice when dry;
pedicel smooth ; teeth ferruginous ; segments broadly split ;
cilia two, as long as the segments ; annulus of a triple row of
cells, remaining attached to the operculum..— Maiit. i. 131;
Bryol. Eur. t. CIO. JI. rugidosum, Web. & Mohr. Jlglocondum
rugosum, DeNot. Briol. Ital. 99.
H a b . Borders of woods, either dry or wet, not uncommon hut generally
sterile: found fertile only at Glen Eyrie, Colorado, on a sandy
slope, by T. C. Porter.
145. H. ro b u s tum , Hook. Stem creeping ; branches very
stout, drooping, yellowish green : leaves densely imbricate, appressed,
homomallous, transversely rugose-striate, distinctly
plicate lengthwise below, scarious, ovate-lanceolate, long-acuminate,
subserrulate toward the apex, bicostate or rarely simply
costate to near the middle ; borders revolute ; cells very n.arrow,
the alar scarcely different ; perichætial leaves whitish, reflexed,
loosely reticulate at base: capsule oblong-cylindrical, cernuous;
pedicel purple ; operculum conical, obtuse, m.amillate. — Muse.
Exot. t. 108 ; Schwaegr. Suppl. iii. t. 261 ; Muell. Syn. ii. 256.
Stereodon rohustus. Mitt. Journ. Linn. Soc. viii. 41.
H a b . Northwestern coast (Menzies); Oregon (Mohr); Fort Colville
(Lyall); Eocky Mountains of British America (Drummond); Northwestern
Montana ( Watson).
Plants large, in dense loose rigid tufts ; stems erect or procuni-
bent, strict, compressed, simple or dichotomous, closely and regularly
pinnate-ramulose ; branches frondiform ; branchlets close.
Leaves falcate-secund, sulcate. Flowers dioecious. Capsule
long-pedicellate, arcuate, cylindrical-oblong. Operculum broadly
conical, .apiculate.
146. H. crista-castrensis, Lmn. Tufts yellowish green ;
stems simple or forking by innovations, rigid, long; branchlets
horizontally divergent, recurved at the apex : stem-leaves broad
and incumbent at base, gradually long lanceolate-acuminate,
twisted, falcate, deeply sulcate, thin, with a short double costa
or none, sharply serrate from the middle upward ; paraphyllia
numerous, long, narrowly lanceolate ; branch-leaves closer,
narrower, falcate-secund, less distinctly serrate, ecostate; perichætium
long-sheathing, whitish ; perichætial leaves deeply
sulcate, ecostate, greenish brown when ripe, dirty yellow when
empty : teeth orange below, pale, serrate and subulate above ;
cilia three or four, thick, as long as the cleft segments ; annulus
simple, narrow. — Spec. PL 1125; Bryol. Eur. t. 599. Stere-
odo/i crista-castrensis. Mitt. 1. c. Ptilium crista-castrensis,
DeNot. Briol. Ital. 101.
H a b . Pine woods, on the ground and old prostrate logs; in mountain
regions.
S uB G EN u s XXII. CTENIDIUM.
Plants with few or no radicles ; branches closely pinnately
ramulose. Leaves circinnate-secund. Flowers dioecious. Capsule
suhhorizontal, short-pedicellate, thick, solid, turgid-ov.ate.
Operculum large, convex, conical-apiculate. — Ctenidium, Mitt.
147. H. molluscum, Hedw. In wide tumescent or fastigiate
soft bright or yellowish green tufts ; stems procumbent or
ascending, generally eradiculose : leaves crowded, circinnate-
faloate downward, flexuous when dry, abruptly narrowly lanceolate
acuminate from a broadly oboordate deourrent base,
sharply serrate all around; areolation very dense, narrow,
minutely round-quadrate at the angles; paraphyllia ovate-
lanceolate; perichætium short, 5-leaved, the inner oblong,