192 H E P A T IC Æ .
14. Portion of mouth of perianth x -85. 15, 16. Perigonial
bracts x 85. 17. Antheridium x 85 (Killarney, S. O. Lindberg).
Genus 16. PLEUROCLADA, Spruce.
Jungermania, Hook. B rit. Ju n g . t. 72 (181G).
Cephalozia, Dum. Recueil, p. 18 (1835).
Pleuroclada, Spruce, On Cephalozia, p. 78 (1882).
Differs from its ally Ilggrobiella by its glaucescent colour
stems radiculose, all the length subsBquifoliate, neither rhizomatous
nor flagelliferous at the base, subpinnate; all branohes lateral, at
the base, near the stem-leaf difformed (monolobed); leaves very
concave (hardly oomplioate) ; perianth very fleshy, below 8 cells
thick, subfloral innovations wanting.
1. Pleuroclada albescens [Hook.), Spruce.
Hook. Brit. Ju n g . t. 72 e t suppl. t. 4 (1810).
CejiJicdozia albescens, Dum. Recueil, p. 18 (1835).
Pleuroclada albescens, Spruce, On Cephalozia, p. 78 (1882).
Dioicous, cæspitose, tufts depressed, eflagelliferous, small to
medium in size, of a whitish or greenish colour, when dry with a
bluish-white tinge. Stems procumbent, laxly subpinnate, sometimes
subdichotomous, slightly radiculose, rooting up to apex of
stem ; firm oval-terete, composed of 5 concentric subequal layers
of opaque cells, cortical about 25, slightly larger than the inner.
Leaves somewhat distant or approximate, patulous, almost transversely
inserted, slightly succubous, orbiculate, very concave,
almost hemispherical, to about the third or a little more bilobed,
segments ovate, triangular, connivent, acute, sinus narrow, acute
or suhobtuse ; cells medium in size, quadrate-hexagonal, 4-, 5- and
6-sided, thick but subleptodermous, almost smooth, slightly endo-
chromio, subpellucid, walls firm, somewhat thick, angles onlj'
slightly thickened, no trigones. Axillary leaf produced partly
from the stem and partly fi’om the adnate branch, difi'ers from the
other leaves in being broadly ovate, subcordate at base, apex acute,
P IE U B O C IA D A . 193
L i .
not bifid. Stipules subcontiguous, appressed, subplane, slightly
shorter than the leaves, broadly ovate or ovate-lanoeolate, aonte or
subacuminate, rarely obtuse, on one side above the base deeply
unidentate, sometimes on both sides or wanting altogether.
Flowers Ç terminal on short or long branohes ; at the base,
copiously radiculose. Bracts 3 pairs, appressed-convolute, subbracts
a little larger than the leaves, bracts almost 3 times larger,
free at the base or slightly connate, oblong-quadrate, bifid to the
third, rarely trifid, segments subacuminate acute, bracteoles
smaller, apex entire or bifid, on both sides near the base with 1-3
large teeth. Perianth highly exserted, 7 times longer than the
stem leaves, clavate or linear-fusiform, deeply trigonous, mouth
constricted, often scariose, afterwards lacerate and erose, texture
firm, near the base 5-8 cells thick, near the middle 2-4 cells, at
about high, 2 cells thick, near the apex composed of a single
layer only ; cells large, elongate, pellucid. Calyptra pyriform,
delicate, only at the base 2 cells thick, where are situated about 8
sterile, somewhat short, lageniform pistillidia, upper portion 1
cell thick. Capsule 4-5 times smaller than the perianth, highly
exserted, cylindrical-oblong ; valves linear-lanceolate or oval, of a
purplish-brown colour like the spores and elaters. Pedicel moderately
thick, cells large, 4-5 times longer than broad, prismatic-
cylindrical, cortical cells 8-9, inner of equal size. Elaters 4 times
shorter than the capsule, filiform, obtuse at both ends, bispiral.
Spores as broad as the elaters, globose, smooth. Androecia?
Fruits May, June.
Dimensions.—Stem to 1 inch long, diameter -2 to A mm.,
with leaves 1' mm. wide; leaves explánate, '5 ram. x '5 mm.,
'65 mra. x '65 mm., ’55 mm. x ’65 mrn., A mm. x '25 mm.,
segments '1 min., '4 mm. x '35 ram., seg. '15 mm., '4 mra. x
'35 mm., seg. '15 mm., '5 mm x '45 mm., seg. '2 mm. ; cells
•025 mm. x '035 mm., '03 mm. x '03 mm., '03 mm. x '025 mm.,
'04 mm. X '025 mm., '033 mm. ; stipules '6 inm. x '3 mm., '5 mm.
x -38 mm., '55 mm. x '4 mra., '3 mm. x '175 mm., '5 mm. x 3 mm.;
sub-bracts-6 mm. x '6 mm., seg. '2 mm., '75 mm. x '7 mm., I'mm.
X '7 mm., seg. '3 mm. ; sub-bracteole '75 mm. x '6 mm. ; bracts
N