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DELESSERIA ALATA, Lamour.
Gen. C h a r. Frond rose-red, flat, membranaceous, with a perourrent midrib.
Fructijication of two kinds, on distinct individuals; 1, spherical
tubercles [coccidia) immersed in the frond, and containing a globular
tuft of angular spores; 2, tetraspores, forming defined spots in the
frond, or in leaf-like processes. D elbsseria [Lamour.),-—in honour
of Baron B. Delessert, a distinguished botanist and patron of Botany.
D elesseeia alata ; stem dichotomous, much branched, winged throughout
with a narrow, membranous lamina which is pennate-nerved ; tubercles
rising from the midrib -, tetraspores in sori occupying the
apices of the frond, or in proliferous leaflets.
D e l e s s e e i a alata, Lamour. Ess. p. 134. Lyngh. Ilyd. Dan. p. 8. t. 3. J g .
Sp. Alg. vol. i. 178. Ag. Syst. p. 350. Rook. El. Scot. p a rt 3. p. 100.
Grev. El. Edin. p. 393. Grev. Alg. Brit. p. 73. Hook. Brit. El. vol. ii.
p. 385. Wyatt. Alg. Damn. No. 14. HaM. in Mack. El. Hib. p art 3. p. 191.
Harv. Man. p. 55.
W o rm s k io ld ia alata, Spreng. Syst. Veg. vol. iv. p. 393.
H y p o g lo s sum alatum, Kiitz. Phyc. Gen. p. 445.
Fuous alatus, ifeife. J ! . p. 578. Gmel. Hist. -ç.H I . Linn.
Mant.-ç.\Zb. S y s t.N a t.-p .n Z . lAghtf.El. Scot.-g.'ibY. El. D a n .t.Z h i.
Stack. Ner. Brit. t. 13. Esper. Ic. Eue. vol. i. p. 30. t. 3. Turn. Syn.
p. 144. Turn. Hist. t. 160. E. Bot. 1 .1837.
H ab. On rocks and the larger Algæ, between tide-marks and in 4-10
fathoms water. All round the British Coasts.
Geogk. D i s t r . Atlantic shores of Europe and North America.
D e s c r . Root, a small disc. Erond, 4 -8 inches high, 1-4 lines in breadth, very
much branched in a more or less regularly dichotomous manner ; the main
divisions being frequently alternate, or almost pinnately disposed, the
minor ones regularly and repeatedly forked. Branches gi-adually narrower
to the tips, consisting of a strong percurrent midrib or stem bordered with a
flat, wing-like lamina, which follows all the divisions, but is usually broader
at one side of the rib than at the other, especially toward the axils, where
there is a deep, rounded sinus. This is most obvious on broad varieties.
Every part of the membrane is furnished with opposite, patent veinlets connecting
the midrib with the margin of the lamina, and themselves connected
by pellucid striæ. Normally the frond is perfectly distichous, all the
branches extending in one plane ; but old specimens are very frequently
beset with crowded, irregulaily inserted branchlets, issuing from all parts of
the midrib proliferously ; such plants are excessively bushy. Tubercles
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