F i c i k im .
i.
P l a t e XXVI.
DELESSERIA RUSCIFOLIA, Lamour.
Gen. Char. Frond rose-red, flat, membranaceous, witli a perou rren t midrib.
Fructification of two kinds, on distinct in d iv id u a ls: 1, spherical
tubercles [coccidia) immersed in th e frond, and containing a globular
mass of angular sp o re s; 2, tetraspores forming defined spots in the
frond, or in leaf-like processes. D e le s s e ria -—in honour of Faron
ij. Belessert, a distinguished Botanist and P a tro n of Botany.
D elesseria ruscifolia; frond lincar-oblong, obtuse, repeatedly proliferous
from th e mid-rib with leaflets of a similar fo rm ; leaflets traversed by
oblique, anastomosing, pellucid s triie ; tubercles on th e mid-ribs of th e
smaller leaflets; tetraspores forming linear spots a t each side of the
mid-rib.
D e l e s s e r i a ruscifolia, Lamour. Ess. p. 134. J g . Sp. Alg. vol. i. p. 175. Ag.
Syst. p. 349. Grev. Alg. Brit. p. 76. Hook. Br. El. vol. ii. p. 386. Llarv.
in Mack. El. H ii. part 3. p. 193. Harv. Man. p. 56. Endl. 3rd Suppl. p. 53.
McCalla, Alg. Hib. no. 13.
WoRMSKioLDiA ruscifolia, Spreng. Syst. Veg. vol. iv. p. 331.
H y p o g lo s s u m ruscifolium, Kiitz. Fliyc. Gen. p. 444.
F u o u s ru sc ifo liu s, T«™. *'» X*»». v o l. v i. p . 127. t. 8. f. 1. Syn.Euc.
p . 11. Hist. 1 .15. Sm. Eng. Bot. 1 .1395.
H ab. Generally growing ou rocks, near low water m a rk ; sometimes parasitical
on other Algae. Annual. Spring, Summer, and Autumn.
N o t uncoimnoii on th e shores of E n g la n d and Ireland.
Geogr. Distr . Atlantic shores of Europe. Cape of Good Hope, W. H . H.
Van Dieman’s Land, Mr. Gunn.
Desc. Root a small disc. Eronds several from the same base, consisting of a
primary leaf 3-4 inches in length, about 4 lines in breadth, linear-oblong,
obtuse, undivided, entire at tbe margin, but often somewhat wavy and curled,
with a ’ strong mid-rib, producing numerous other leaves in a proliferous
manner, aU of similar shape to the primary ; and these again producing a
tbii-d and fourth set, until there results a much branched frond. All the
leaflets spring regularly from the mid-ribs of those first formed. The cellules
composing the membrane of the leaves are very minute, angular and
closely packed ; but the substance is traversed with branching and anastomosing,
pellucid, jointed striæ or veinlets, composed of a single string of
elongated cellules, and running in an oblique direction, from the mid-rib to
the margin. Tubercles seated on the mid-ribs, generally toward the apices
of the younger leaves. Sori linear, elongated, forming interrupted lines at
each side of the mid-rib. Colour, a transparent blood-red. Substance more
rigid than in B . Hypoglossum.
Delesseria ruscifolia was discovered on the Yarmouth shore by