Ser. RuoposPERME®. Fam. Delesserie. 
Piate CCXLVII. 
DELESSERIA ALATA, Zamour. 
Gen. Cuar. Frond rose-red, flat, membranaceous, with a percurrent mid- 
rib. Fructification of two kinds, on distinct individuals ; 1, spherical 
tubercles (coccidia) immersed in the frond, and containing a globular 
tuft of angular spores; 2, ¢e¢raspores, forming defined spots in the 
frond, or in leaf-like processes. DxEtEsspri1a (Zamour.),—in honour 
of Baron B. Delessert, a distinguished botanist and patron of Botany. 
Detesseria alata ; stem dichotomous, much branched, winged throughout 
with a narrow, membranous lamina which is pennate-nerved; tu- 
bercles rising from the midrib; tetraspores im sori occupying the 
apices of the frond, or in proliferous leaflets. 
Devesseria alata, Lamour. Ess. p.124. Lyngb. Hyd. Dan. p.8.t.2. Ag. 
Sp. Alg. vol. i. 178. Ag. Syst. p. 250. Hook. Fl. Scot. part 2. p. 100. 
Grev. Fl. Edin. p. 293.  Grev. Alg. Brit. p. 73. Hook. Brit. Fl. vol. ii. 
p- 285. Wyatt. Aly. Damn. No. 14. Harv. in Mack. Fl. Hib. part 3. p. 191. 
Harv. Man. p. 55. 
WormskIo.Lpia alata, Spreng. Syst. Veg. vol. iv. p. 293. 
Hypoctossum alatum, Kitz, Phyc. Gen. p. 445. 
Fucus-alatus, Huds. Fl, Ang. p.578. Gmel. Hist. p. 187. t. 25. f.1. Linn. 
Mant.p.135. Syst. Nat. p. 718. Lightf. Fl. Scot. p.951. Fl. Dan. t. 352. 
Stack. Ner. Brit. t.13. Esper. Ic. Fue. vol. i. p. 20. t..3. Turn. Syn. 
p. 144. Turn. Hist. t. 160. E. Bot. t. 1837. 
Has. On rocks and the larger Alge, between tide-marks and in 4-10 
fathoms water. All round the British Coasts. 
Geogr. Distr. Atlantic shores of Europe and North America. 
Descr. Root, a small disc. Frond, 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 gradually 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 con- 
necting the midrib with the margin of the lamina, and themselves connected 
by pellucid striae. Normally the frond is perfectly distichous, all the 
branches extending in one plane; but old specimens are very frequently 
beset with crowded, irregularly inserted branchlets, issuing from all parts of 
the midrib proliferously; such plants are excessively bushy. Tudereles 
VOL. III. D 
