!
i'i
l'3 mm. X '9 mm., l'mm. x ’8 mra., seg. A mm. ; bracteole 1' mm.
X '55 mm. ; perianth 4’ mm. x A-AS imii. ; qredioel 10'-15’nim. ;
capsule A mm. x A mm., valve 7 mm. x '275 mm. ; spores
0125 mm. diam. ; elaters '2-'25 mm. x '0125 ram.
H a b.— t)n damp earth in alpine localities, rare.
1,5. Clova, E. K. Greville. Ben Mac ühui, G. E. Hunt, Thomas
Rogers, G. Stabler. Beu Lawers, G. E. Hunt. Head of Loch Avon,
A. Croall. 16. Ben Nevis, R. K. Greville.
Found on the Continent and in North America.
Obs.—A very distinct species, and only found near the tops of
tlie highest Scotch mountains ; from any of the Cephalozice distinguished
at once by the lateral branches ; from P. islándica
(Nees). see notes under that species.
D e s c r ip t io n o f P l a t e LXXV.— Fig. 1. Plants natural size,
2. Portion of stem, antical view x 16 (Clova, E. K. Greville).
3. Ditto, postical view x 24 (ditto). 4, 5. Leaves x 64 (Grimsel,
G. E. Davies). 6. Portion of leaf x 290 (Clova, Greville). 7.
Stipule x 64 (Grimsel, Davies). 8. Ditto x 85 (Clova, Greville).
9. 3rd sub-bract x 24 (Lapland, Angstrom). 10. 2nd sub-bract
X 24 (ditto). 11. Sub-bracteole x 24 (ditto). 12, 13. Bracts
X 24 (ditto). 14. Bracteole x 24 (ditto). 15. Perianth x ?
(G. & E. Hep. Eur. n. 468, drawn by Dr. Gottsche).
2. Pleuroclada Islándica {Nees).
Jungermania islándica, Nees Nat. Eur. Leb. 11, p. 21) (1836).
Cephalozia islándica, Lindb. in Journ. Linn. Soc. xiii. p. 192 (1873).
Pleuroclada albescens, var. islándica, Spruce, On Cephalozia, p. 79 (1882).
Dioicous, cæspitose, tufts depressed, eflagelliferous, small, pale
green in colour, when dry with a bluish-white tinge. Stems
simple or sligbtlv branched, oval-terete, cortical cells about 20,
similar to the inuei', 8 cells in diameter ; radiculose, rootlets few,
white ; branches lateral. Leaves imbricate, near the apex of stem
approximate or somewhat distant below, patent to ereoto-patent
(40°), orbicular, oomqilicate-conoave, bifid to the middle or below,
sinus obtuse, segments broadly lanceolate or triangular, acute.
connivent; texture somewhat thick, cells 4-, 5-, and 6-sided,
smallish, walls thick, no trigones or thickened angles. Stipules
large, as long as tlie leaves, ovate-lanceolate, entire. Flowers ¥
terminal on long branohes. Bracts oblong or oblong-ovate, bifid
to below the middle, segments laneeolate-aouminate. entire ; bracteole
free or adnate to one of the bracts, much smaller than the
bracts, oblong-ovate or ovate, retuse, emarginate or entire ; sub-
braots similar to the innermost, only smaller. Perianth projecting
much beyond the bracts, linear or narrowly fusiform, cylindrical
below, above deeply 4-5-plieate, folds obtuse, composed of a single
layer of cells, near the middle about 80 cells round, mouth oon-
strioted, irregularly and slightly dentate. Calyptra delicate,
composed of a single layer of cells. Fruit and male stems not
yet known.
Dimensions.—Stems | to 1 inch long, diam. T75 to '2 mra.,
with leaves '5 to '75 mm. wide; leaves A mm. x '25 mm., segments
-125 inm., -275 inm. x '25 mm., seg. -125 mm., 25 mm. x '225 mrn.,
seg. -15 mm., -4 mm. x A mm., seg. ’225 rnm.; cells '02 mm.x’
-025 mm., 0225 mm. x '0225 ram., '03 mm. x '025 mm.. 02 mra.
x-02 mm..; stipules '3 mm. x -125 mm., -35 mm'x-15 mm.,
-25 mrn. X '1 mm., -275 mm. x -15 mm. ; sub-braots -75 mm. x
•5 mm., seg. '4 mra., -9 mm. x '45 mm., seg. -55 mra.; bracts
1- mm. X -6 ram., seg. '6 ram.; perianth 2' mm. x '5 mm., teeth
at the mouth '04 mm.
H ab.—Moist rocks or earth in alpine situations. Extremely
rare. 15. Loch-na-gar, Aberdeenshire, J. Sim, April 1878.
Found m Iceland, Northern Europe and Greenland.
Obs.—Differs from P. albescens (Hook.) in the more slender
habit of the plant, closer, more erect leaves, which are usually
narrower, with deeper sinus, much less concave, not hemispherical,
but simply complicate-concave, stipules narrower with no basal
tooth or teeth, bracts longer and narrower, deeply bifid to below
the middle, segments lanceolate-acuminate, not to a third, with
segments subacumiuate-aoute, bracteole retuse, emarginate or
entire, with no basal teeth, perianth narrower, more plicate near
the apex, composed of a single layer of cells, not several. Con