72. I I . m t n i i t i s s im i im , Snlliv. & Lesqx. (Muse. Bor.-Amer. No. 343.)
Moncecious ; stems capillary, irregularly branched ; loayes ecostate, subcntire,
those of the stem narrowly lanceolate from a broadly ovate base, widely spreading
; branch-leaves much smaller, llnear-lancoolato, subappressed ; capsule obo-
vate, inclined, cemuous ; operculum large, hemispherical-conic, apiculate ; an.
nulus simple, narrow; inner peristome ciliolate; perichætial loaves strongly
and irregularly serrate. (Muse. Allcghan. No. 31.) — Grows with H. pygmæ-
um, in close, thin, deep-green strata, on limestone rocks; in shaded ravines,
Pcmi. .and Ohio. — The smallest of om- Hypna, Closely allied to H. confer-
voides, Schwoegr., and II. Sprucoi, Bmch : the first is twice as large, and has a
pinnate ramification, an oblong capsule, and entire pcrichætial leaves : the second
is dicecious, with çiliate-dentato perichætial leaves ; but in all other respects
(oven in the capsule, which is erroneously described as erect and regidar) it
approaches very near to ibis species.
73. I I . a d n ù t u u i , Hedw. Monoecious ; loaves closely imbricated, ovate
and ovate-lanceolate, suddenly acuminated, concave, shortly bicostato, the margins
nearly entire aud reflexed below ; capsule oblong, erect-cernuous ; perichætial
leaves irreguliirly denticulate.—A small species, growing iu thin, close
mats, on stones near the surface of the ground ; seldom on trees.
II- I I . s e r p e n s , Hedw. Monoecious ; stems sparingly divided, closely
ramulose ; branches simple, filifoiTn, unequal, flexuous-erect ; leaves spreading,
ovate-lanceolate, acmninate, entire or obsoletely serrulate, costate about half-
way ; areolation rather largo and pellucid ; capsule clongated-cylindiical, cernu-
ous-incurvcd, broadly annulate. — On rocks, decayed logs, and the ground. —
Subject to many varieties. (Eu.)
75. I I . r a t l i c à l e , Brid. (Bryol. Europ.) Monoecious; closely related
to the preceding, but larger and more rigid ; leaves entire, longer and more
suddenly acuminated from a broader and rounder base, with a stouter costa
extending to the ap e x ; areolation closer. (H. varium o f authors.) — Same
localities as the last ; likewise veiy variable. — (In Bryol. Europ. a new species,
Amblystegium seiratum, near this, is indicated, with smaller strongly serrated
loaves and a shorter costa ; founded on specimens from Beading, Penn.) (Eu.)
76. I I . o l ' t l i o c l a d o n , Beauv. Monoecious; larger than II. radicale,
with longer, thicker, succulent, upright and straight branches (whence its specific
name) ; leaves flaccid, entire, shorter-acuminate from a broad cordate
base ; costa continuous ; areolation smaller. — Wet springy places.
77. H. n o t c r o p h i l u m , Sulliv. & Lesqx. (Muse. Bor.-Amer. No. 348.)
Monoecious ; divisions of the stem with an irregular pinnate ramification ; loaves
of the fertile stems broadly ovate-lanceolate, shortly acuminate, crect-spreading,
with a strong excurrent costa ; those of the thick and firm immersed sterile
stems erect, appressed, narrowly linear-lanceolate, gradually tapering from an
ovate base, long-cuspidate by the heavy costa, which occupies nearly J of the
lamina ; capsule elongated-cylindrical, erect-incurved, narrowly annulate. (II.
fluviatile, James, in Proceed. Acad. Nat. Sci. Phil. 1855.)—Abounds in limestone
springs, Franklin County, Penn., Prof. Porter. — A stout, rigid, dark-
green Moss, resembling Amblystegium irriguum, var. fallax, Bryol. Europ. fasc.
Íi
55, 56, emend., but is a larger plant, the leaves nan'ower and entire, with a much
heavier costa. Tho true Swartziaii II. fluviatile of Wds. Bryol. B r it ; Bmol.
Europ fasc 6 2 - B4, is a soft aud flaccid plant, the ramification not pinnate.
H noterophilum appears not unlike H. filidnum, var. ValUselausæ, Bryol. B r it
(H. Vallisclausæ, Brid.), but diflers iu the inflorescence.
78. II. riiiàrillin, Hedw. Monoecious; stems much elongated, the dissio
n s distantly aud suhpinnately branched; leaves usually remote, bifariously
directed, ovate and oblong-lanceolate, acuminate, entire, costato half-way ■ thin •
areolation minute, linear-rhomboidal ; capsule oblong, cemuous. - Common’
about swamps ; also on stones in rivulets. — Quito variable. (Eu.)
79. II. p o l y g a m n m , Bryol. Europ. Staminate, pistillate, and hermaphrodite
flowers in clusters, and on tho same stem; stems procumbent or
ascoiidmg, irregularly aud subpinnatcly branched ; leaves entire, spreading, subsquarrose,
long and subulately acuminated from a concave, cordate, or ovate-
lauceolate base, the point variously directed, costate half-way, or more or less
distinctly bicostato at the base, scarious ; areolation minute, linear ; the cellules
at the deeurrent angles enlarged, oblong; capsule oblong, cernuous, broadly
annulate. — Swamps, British America, Dranimond — Very much like I I stcllatum,
but somewhat smaller, and not so harsh a species.
80. H, liC S C U ril, Sulliv. (Muse. Bor.-Amer. No. 350.) Monoecious •
stems prostrate; branches erect, simple or divided; leaves lax, widely spreading,
broadly ovate, very shortly acuminated, concave, with a tliickened yellowish
border composed of several Hnes of linear flexuous cellules, which elsewhere arc
rhombic-oval; costa stout, extending to tlie serralate point; capsule oblong,
coruuons, broadly annulate ; operculum acutely conic. — On wet rocks, T a ll7
lab Falls, Georgia, Lesquereux. Also Brattleborough, Vermont, Frost
§ 21. PLAGIOTHÈCIUM, Bryol. E u ro p .-S em s procumhent or erect, spar-
inyly branched; branches usually subcompressed or complánate, dongated, assurgent
mostly simple: leaves mate and ovate-lanceolate, more or less unsymmetrical, ecol
tate or shortly bicostate; areolation dongated-rhomhoidal, or linear a nd flexuous-
capsule oblique, cylindrical, moderately curved, sometimes oblong, erect, and equal.
* Inflorescence monoecious.
81. H. d e n t iC M l à t o n i , L. Stems prostrate, 2 ' - 3 ' long, stoloniferous ■
leaves obliquely ovate-aciimiuate, shortly hicostate, decurrent, the margins narrowly
rcflexed; areolation narrow aud elongated; capsule oblong inclined-
operculum conic, acute; annulus large, compound: pedicel red .—In loosé
tufts, on tussocks, in swamps and crevices of moist rocks : variable. — On the
White Mountains, N. Hampsliire, occurs what may be a form of this species;
but It is smaller, with an upright growth, and an erect regular and naiTowlé
annulate capsule ; according well with Plagiothecium lætum, as given in Bryol
Europ., except that its inner peristome is ciliolate, and even in this respect not
differing from specimens received from W. P . Schimper under that name. (Eu.)
_ 82. II. M u l i l e i l b ó c k i i , Bryol. Europ. Stems scarcely 1 'long, ascending
; braiiclios short, arcnate-ercot, fasciculate ; leaves complánate, ovate-lanceolate,
long-acuminate, subsecund, serrulate, shortly bicostato, decurrent; cellules
at the basal angles large and inflated, elsewhere much .smaller, elongated