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PLEUROCHÆTE SOUARROSA (Brid.) Lindb.
Dio icous ; la xly tufted. L e a v e s squarrose from a broad sheathing
base, lan ceo la te , serrate at point. Se tæ la teral, caps, subcylindric.
(T . X X X I I I , D.)
S\N.— Bai-hda squarrosa B r i d . Bry. univ. i, 833 (1S27). B r u c h S c h im p . Bry. eur, f, 31,
Suppl. t. I (1846). C. M u e l l . Synops. i, 601 (1849). S c h im p . Synops. 180 (i860),
2 ed. 221. B e r t o l . Fl. ital. cr. 207 (1858). M i l d e Bry. siles. 124 {1869). H u s n .
mouss. nord-ouest 84 (1S73). J u r a t z . Laubm. oesterr.-ung. 124 (1882). L e s q . J a m e s
Mosses N. Amer. 130 {1S84).
Tortula squarrosa D e N o t . in Mem. ac. Torin. xl, 321 (1838), Syllab. 180 (1838), Musc.
ital. I, 61, t. 31 (1862). S p r u c e in H o o k . L. journ. iv, 193 {1845), et Ann. Mag. n. h.
2 ser. iii, 377 (1849). W i l s . Bry. brit. 126, t. 33 (1855). M i t t . Journ. Lin. soc. i,
Suppl. 27 (1859). B e r k . Handb. br. m, 255 (1863). H o b k . Syn. br. m, 74 (1873).
Plcurochoete squarrosa L in d b . d e T o r t . 253 (1S64). D e N o t . E p i l. b r i. ita l. 560 (1869).
D io icous ; la x ly and irregularly cæspitose, tu fts yellow-green above,
fuscescent at base, fragile, not tomentose. Stem simple or d ich o to mous.
Le a v e s comant at apex o f stem, from a broad sheathing base,
recurvo- and incurvo-squarrose, fla ccid and cirrato-crisp ate when dry,
e longate-lanceolate, subundulate at margin, serrate abov e, nerve thick,
vanishing at apex or excurrent ; a reolation minute, chlorophyllose and
rectangular above and a t mid base, v ery finely papillose, a t sides o f base
thin la x and hyaline. Pe richæ tia numerous, la tera l, the b ra c ts shorter,
semivaginant, reflexed: se ta red below, ye llow ish -ab o v e, ca lyp tra v ery
narrow, fugacious, caps, erect, cylindra ceous, subarcuate, deep rufous,
annulus narrow o f a single series o f cells, lid conico-subulate, per. pale
purple, tw ic e convo lute, fugacious, teeth v e ry slender, short-jointed,
strongly papillose.
PIa b .— B are s ton y ground on the south co a s t and in ch a lk y fields. F r . 5— 6.
Beedlng chalk-pit, Sussex (Borrer). Shoreham beach (Wilson 1837) I ! Woolsonbury
hill {Mitten). Between Brighton and Newhaven [Davies 1868) ! ! Tothill, Plymstock,
St Minver and Berryhead [Holmes) ! ! Minehead, Somerset [Boswell 1867) ! ! Holton,
Oxîovà [Boswell) \\ Portmarnock, Dublin (Tay/or). Arklow, Wicklow (Afoore). Wm-
chelsea [Holmes). Ballard down, Swanage [Holmes). Lathkill dale, Derbyshire
[Whitehead 1882) ! ! Holton stone pits, Oxford [Boswell) ! !
F o r the b eautiful fertile specimen figured, I am indebted to my friend
Mr. Bo sw e ll, in this co u n try it is a lw a y s sterile. T h e re is something in the
look o f the p lan t v e ry different from a ll our other species and ap p roa ching
that of Leptodontium.
7. M O L L IA S c h r a n k .
Baiers. FL ii, 455 (1789).
Plan ts dw a r f or ta ll, cæspitose or pulvinate, dichotomously
branched. L e a v e s lan ceo la te , papillose, bright or dark green, usually
crisped or contorted when dry, th e areolation la x and hyaline at base,
minute obscure and chlorophyllose above. Capsu le in a few cases
with an adherent lid, or gymnostomous, the mouth being sometimes
closed by a membrane, or with a peristome consisting o f a narrow
basal membrane supporting i 5 te e th , more or less developed, papillose,
c le ft to base into two equal or irregular legs, straight or occa sion ally
contorted. Inhabiting the ground, walls or ro ck s .— Der, after K. E .
von Moll, Archbishop of Salzburg, author o f “ Naturhist. Brièfe ueber
S a lz b u r g ” (1785).
The genus Mollia, founded by Schrank as an equivalent to Tortula or
Barhula, may well be retained for this group, as Trichostomum was established
by Hedwig in 1782, for the section of Grimmia named Rhacomitrimn and some
species of Ditrichum, and it was not until more than 20 years after this
that any of the species now referred to Trichostomum were brought into it.
Taken as a whole, we must look upon the genus Mollia as an eminently
natural one, ascending from several little phascoid mosses, through a series
of closely allied forms, to the taller species culminating in M. tortuosa, all
marked by their narrow opake papillose leaves, curled or twisted when dry,
and a peristome of one common type, presenting various stages of development.
A little study of the species will soon convince the student that
Systegimn, Weissia, Gymmstomum, Didymodon, Hymenostoiimm, Eucladium, Gyro-
weissia, Leptobarbula have no sound basis as genera, but may be readily
distributed in the three sections adopted.
Hymenostomum stands to Mollia almost exactly in the same relation as
Pottia does to Tortula, and we see in the species it includes, only miniatures
of the larger forms of the third section, and just as closely allied to each other
as certain Pottias are.
In Tortella a very important character may be noticed in the relation of the
two kinds of cells composing the leaf base, in some species the white thin
elongated hyaline cells meet the small chlorophyllose cells at the same level
from nerve to margin, in others at a certain height, the hyaline cells leave the
nerve and ascend obliquely outward to the margin, so that the demarcation
between the two is very distinct.
Besides the continental species incidentally referred to in the text,
the second edition of Schimper’s Synopsis contains a number of others,
both in this genus and the last, which it may be useful to enumerate, as attention
is thus drawn to them, though except Tortula cernua and inermis, it is not
probable that any of them will be met with here.
Under Tortula in the section Desmatodon, we find T. squamigera (Viv.),
B. membranifolia Schultz,— T. crassinervis D e N ot., B. cUoronotos B. & S.—
Gttepini B, & S.— anomala (B. & S.)— harbuloides (B,mo.)—flexiseta (B ruch.) —
systylia (B, & S.)— latifolia (H edw.)— cütom (Hueben.),— limbata (L indb.)—
obtusifolia S chleich. D. fiavicans (B. & S.),— Solmsii S chimp. the last three
near T. marginata ; in Zygotrichia, T. Laureri (Schultz) and T. suberecta
H ook., D. obliquas B. & S. and in Syntriehia, T. alpina (B. & S.)
Under Mollia in Sect. Hymenostomum, we have M. muralis (S pruce),—
crispata (N ees Hornsch.),— Wimmeri (S endtn.),— Welwitschii (Schimp.),—
triumphans (De N ot),— Monspeliense (Schimp.)— berica (De N ot.),— meridionalis
and Winteri (Schimp.) ; in Eucladium, M. refiexa (B rid.) near tenuis,— Philiberti