ii
I ;
Nerve J w i d t h o f b a s e ; cells lax rec tangular and pellucid at base, the
angular large hyaline numerous, th e upper chlorophyllose, the teeth
hyaline. Perich. b ra c ts like the lea ves, v ery broad at base, sh e a th in g ;
se ta elongated yellow e re c t, tw isting to th e left when dry, capsule erect
pale brown, cy lin dric-ova l, con tra c ted below the mouth, p lica te when
old, lid conic with a subulate nearly stra igh t beak about as long as
c ap su le ; teeth pale red, cleft h a lfw a y into tw o unequal legs.
Male infl. gemmaceous, inner b ra c ts suddenly sh ortly acuminate,
the nerve thin or sca rce evident.
H a b .— On sandstone rocks in mountain districts ; always sterile.
Lennox castle, Campsie and Ben Ledi {McKinlay i86r) ! ! Ben Mac Dhui {Dickie 1861) !
Mains Castle, New Kilpatrick {Galt 1865) ! ! Ben Voirlich {McKinlay 1865) !
Milngavie, Glasgow {Stirton 1S64)! Bach-na-gairn, Clova {Fergusson 1868). Ben
Hope, Sutherland {Howse 1871) ! ! Debris of rocks by Loch Avon, Braemar
{Hunt 1871) ! !
Very unsettled opinions have been held by bryologists with respect to
this moss and the next, probably influenced to some extent by the fact that
they frequently grow together, and that D. asperulum is variable in the roughness
and direction of the leaves, so that some forms are difficult to discriminate,
not only from D. uncinatum, but still more from Didymodon denudatus,
which it closely resembles in structure. The clear definition of the species
by Mr. Mitten in his Musci Indise or. drawn up from fertile specimens (with
which the British plant is certainly identical), shows that however closely in
habit and leaf-structure it r e s e m b l e s denudattis, it cannot be congeneric,
for as a genus that must stand on the form of its peristomial teeth, but those
of D. aspertdmn are perfectly dicranoid. W e may contrast the species thus :—
D. asperulum. Dull green, stems slender scarcely tomentose, leaves dense, variously
flexuose, erecto-patent, uppermost slightly falcato-secund, margin of basal wing serrated,
subula closely serrated, scabrous at back.
D. uncinatum. Yellow green, rather glossy, stems robust tomentose, leaves more distant,
all regularly falcato— or circinato— secund, margin of basal wing, entire, subula
distantly denticulate in upper part, smooth at back.
Didym. denudatus. Known at once by its large basal auricles, with large lax hyaline
cells.
An elaborate paper by Milde, “ Ueber Dicranodontium,'' in Botan. Zeitung,
1870, pp. 392 and 414, is well worth consulting, although we differ from some
of his conclusions.
21. DICRANUM UNCINATUM {Harv.) C. Muell.
Dio icou s ; ta ll g los sy yellow-green ; leaves s trongly falcato-secund,
from a dilated base, longly subulate, denticula te toward apex, c e lls at
base lax quadrate, with a border becoming broader upward o f very
narrow elongated on e s ; caps, e re c t subcylindric, lid ros trate. (T.
X X IV , C.)
Thysanomitrium uncinatum H a r v e y in H o o k . I c . pl. rar. i, t. 22, f, 5 (1837), et Lond
Journ. Bot. ii, p. 6 (1840).
Dicranum uncinatum C. M u e l l . Synops. i, 404 (1849). M i t t , in Journ. Lin. Soc. i,
Suppl. 21 (1859).
Dicranum circinatum W i ls . Bry. brit, 76 (1855). Schimp. Bry. eur. Suppl. fasc. III-IV, t,
4 (1866). Hobk. Syn. br. m. 47 (1873).
Dicranodontium asperulum p.p. W i ls . in Kew Journ. Bot. IX, 296 (1857).
Dicranodontium circinatum S c h im p . Synops. 2 ed. 100 (1876),
Dicramim comptum S c h im p . Synops. 2 ed. 97 (1876).
Dioicous ; la xly cæspitose, glossy golden green or fulvous. Stem
slender flexuose, 2— 5 in. high, dichotomous, geniculato-a scending, more
or less rufo-tomentose. L e a v e s rather distant, enlarging upward, lowest
lanceolate, upper v ery long, secund circinate, from a decurrent sheathing
base slightly inflated at the angles, suddenly longly subulate, cana licu la
te ; nerve i width o f base, o f 3 s tra ta o f cells, produced into a very
long a rista, d en ticu la te a t b a ck and margin ; ce lls at angles and midbase
large thin hyaline, hexagono-rectangular, marginal in 4— 8 rows o f
very long narrow green c e lls . Perich. b ra c ts from a la x ly areolate,
shortly sheathing base, gradua lly capillaceous, seta short, fulvous,
straight or flexuose, caps, e re c t subcylindric, castaneous-brown, lid with
a long beak, teeth purple, c le ft h a lf way, th e legs subulate.
H ae .— We t grassy places on mountains ; sterile, not common.
Ben Voirlich by Loch Lomond (GreviUe 1825) ! ! Ben Mac Dhui [Davies i86r) ! ! Ben
Nevis [McKinlay 1862) ! Ben Challum, Perthshire, with D. aspernhim [McKinlay
1863) ! ! Loch Maree (Hunt 1866) ! ! Glen Phee, Clova (Fergusson 1867) ! !
The basal areolation is much firmer than in the last species, and the
marginal border o f very narrow cells much more distinct. Although Harvey
placed the species in the genus Thysanomitrium, he must have done so at
random, as the calyptra has never been described.
Subf. 5. ON CO PH O R EÆ . Plants densely or laxly tufted; leaves
chlorophyllose, opake, usually papillose, without enlarged basal angular
cells, the upper cells minute, quadrate. Capsule oblong or subcylindric,
frequently striate, usually with a strumose neck.
14. D IC H O D O N T IU M S c h im p .
Bry. eur. Coroll. p. 12 {1855).
P lants la x ly tu fted , soft. L e a v e s squarrose, c renato-serrate,
papillose, opake, cells re c tangular a t base, quadrate above, ch lorop hy llose.
C a ly p tr a large, cu cu lla te ; capsu le solid, pachydermous, smooth,
lid rostrate, peristome large, teeth i6 , cleft below the middle into 2— 3
legs, c lo se ly trabe cu la te .
Inhabiting wet rocks and stones b y streams.
D e r .— bigaoi to divide, oSovs a tooth.
C lavis to th e S p e c ie s .
Capsule cernuous, gibbose ovate ; leaves serrulate at apex.
Capsule erect, subcylindric ; leaves serrated in upper half.
pellncidzan.
ftavescens.