Ser. CuLOROSPERME”. Fam. U/vacee. 
Piate CLXXI. 
ULVA LATISSIMA, Linn. 
Grn. Cuar. Frond membranaceous, green, expanded, plane, (in some 
cases saccate when young,) composed of irregular cells. Fractifica- 
tion; granules, often arranged in fours, scattered over the whole frond. 
Uxva,—supposed to be from UZ, water, mm Celtic. 
Utva /atissima; frond broadly-ovate or oblong, flat, of a full green colour. 
Utva latissima, Linn. Fl. Suec. p. 433. Ag. Sp. Alg. vol. i. p. 407. Ag. 
Syst. p. 188. Grev. Alg. Brit. p. 171. Hook. Br. Fi. vol. ii. p. 311. 
Wyatt, Alg. Danm. no. 33. Harv. in Mack. Fl. Hib. part 3. p. 242. 
Harv. Man. p.170. J. Ag. Alg. Medit. p.17. Kitz. Phyc. Gen. p. 296. 
Mont. Fl. Alg. p.149. Endl. 3rd Suppl. p. 19. 
Uva lactuca, Sm. H. Bot. t. 1551. (not of Linn.) 
Utva lactuea, var. latissima, Lightf. Fl. Scot. p. 971. 
Has. On rocks and stones in the sea between tide marks; and extending 
to ten fathoms water, or perhaps a greater depth. Annual. Summer 
and autumn. Very common on the British shores. 
Groce. Distr. Throughout the ocean, nearly to the limits of vegetation in both 
hemispheres. 
Descr. Root, a small disc. Fronds from six to twenty inches in length or more, 
and from three to twelve in breadth, growing in tufts; very variable in 
shape, oblong, or ovate, with the margin more or less sinuated and wavy, 
variously plaited, glossy, translucent, of a very soft, but rather firmly 
membranous, though exceedingly thin, substance, and vivid green colour. 
In old age the fronds are frequently found pierced by holes, and infested 
with Myrionemata, and are then usually of a pale green colour. Sometimes, 
especially in specimens dredged from deep water, the colour is of a very 
dark, and even bluish green, reflecting glaucous tints when under water. 
In drying, this plant loses much of its brillianey, and scarcely adheres to 
paper. Structure composed of two strata of exceedingly small, fully 
coloured cells of regular shape, separated by an imperfectly coloured, 
thin, cellular layer. 
An exceedingly common species, found on all shores, and 
nearly in all latitudes. Except on the extreme antarctic coasts, 
where all vegetation, save the Diatomacee, is at an end, Ulva 
latissima may be said to inhabit every shore. It is as abundant 
in the tropics as in the temperate zone. Nor do specimens from 
different countries exhibit many minor points of difference. Some 
are of more rigid texture than others, but there is little else pecu- 
har about them. The form is too variable among specimens 
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