P l a t e X.
POLYSIPHONIA RICHARDSONI, Hook.
Gen. C h a r . Frond filamentous, partially or generally articu la te ; joints
longitudinally striate, composed internally of parallel tubes or elongated
cellules. Fructification two-fold, on distinct p la n ts ; 1, ovate
capsules {ceramidia) furnished with a terminal pore, and containing a
tu ft of pear-shaped se ed s; 3, tetraspores imbedded in swollen branchlets.
PoLYSiPHONiA— from noKxis, many, and a tube; because
th e axis of the frond is composed of many tubes.
POLYSIPHONIAffic/iar&OM; stems cartilaginous, setaceous; branches alternate,
elongated, divaricate, beset in th e upper p a rt with very patent,
straight, sub-dichotomous ram u li; articulations of th e stem and
branches two or three times longer th an broad, irregularly veined ;
of th e ramuli sh orter; capsules sessile, globose.
POLYSIPHONIA Eichardsoni, Hook. Br. M. vol. ii. p. 38. Harv. Man. p. 90.
H ab. Yery rare. F t Coheaà,T)maînes, B r. John Richardson.
G e o q e . D is t r . South-west of Scotland.
D e s c . Boot scutate. Frond 3 -4 inches long, setaceous, rather rigid, with a
suhdistinct, zig-zag stem, very much branched from a short distance above
the base ; the branches issuing at right angles, angularly bent, as long as
the main stem, subquadrifarious, mostly alternate, beset with distant, very
patent, subdichotomous, straight branchlets, which hear a few mostly simple,
erecto-patent or erect, subulate ramuli. Articulations visible in the
main stem, subtorulose, the lower ones thi-ee or four times longer than
broad, spirally or in-egularly tubed ; the upper shorter, with parallel tubes.
Capsules globose, sessüe, wide-mouthed, situate near the summits of the
lesser branches. Tubes about five in the stem, each with a deep-coloured
hag of eudoclu'ome.
Wliat little is known of tliis species, if it be entitled to tbat
rank, is taken from a specimen gathered by Dr. Richardson many
years ago, before the Arctic Expedition which he accompanied,
and preserved in Sir W. J. Hooker’s rich Herbarium. Our uppermost
figure is nearly a fac-simile of that specimen.
Though it closely borders in its microscopic characters on
several species, its habit does not precisely agree with any
with which I am acquainted. The nearest in affinity is perhaps
-P. fihrillosa, and it is possible that it may be only an anomalous