ULVA. 



and fufEciently well marked by the arrangement of its 

 feeds, by which it differs from Fucus. The Enghfti name 

 Laver is well applied to the genus before us. — Linn. Gen. 

 567. Schreb. 768. Mart. Mill. Dift. v. 4. Dill, in Raii 

 Syn.62. Sm. Prodr. Fl. Grsec. Sibth. v. 2. 331. Hiuif. 

 566. Roth Catal. V. I. 204. Jufl". 6. Lamarck lUuftr. 

 t. 880. — Clafs and order, Cryplogamia Algic, Linn. Nat. 

 Ord. Algx fubmerft. 



Eflf. Ch. Frond membranous or gelatinous. Seeds fo- 

 litary, fcattered throughout its fubftance, under the cuticle. 



Fewer difficulties attend the generic charafter of Ulva 

 than that of feveral other marine Algx, yet various things 

 have been improperly referred to this genus. (See Rivula- 

 RIA.) Some excellent remarks on this fubjedl are given by 

 Mr. Woodward, in Tr. of Linn. Soc. v. 3. 46 ; and the 

 fame is ably treated by Dr. Roth, in the firft volume of his 

 learned CataleSa, above cited. We iliall follow the laft- 

 mentioned author in his leading principles ; regretting that 

 we are (till deprived of a more compLte view of the whole 

 genus, long promifed by Mr. Dawfon Turner ; who in his 

 peculiar attention to this natural order of plants, has en- 

 joyed more opportunities than any other botanift, for their 

 complete elucidation, Thefe opportunities however may 

 perhaps have ferved to make him the more fully aware of 

 the difSculties of the undertaking. With refpeft to the 

 exiftence of fpecics, in which, as Mr. Woodward obferves, 

 " no aftual fruftification has been hitherto difcovered," we 

 can only fay that thefe are referred by analogy of habit to 

 Ulva, with which they accord at leaft as well as with any 

 thing elfe, the fame dcfeft which renders their place here 

 doubtful, difabhi.g us from removing them elfewhere. We 

 fliall enumerate all the known Britifh Ulvt, with fuch ex- 

 otic ones as appear to be well determined, aiming rather at 

 giving a general idea, than a complete view of the genus. 



Seft. I . Frond expandtd, leafy. 



1. U. pavonla. Turkey-feather Laver. Linn. Syft. 

 Nat. ed. 12. v. 2. 719. Sm. Prodr. Fl. Grsec. Sibth. 

 n. 2515. E'lgl- Bot. t. 1276. (Fucus maridmus, gallo 

 pavonis pennas referens ; Raii Syn. 43. Tourn. Inft. 568. 

 Ellis's Corallines, 88. t. 33. f. <r. D,'E. Morif. left. 15. 

 t. 8. f. 7.) — Frond membranous, flat, kidney-fhaped, with 

 a taper bafe. Seeds in tranfvcrfe arched lines. — Found at- 

 tached to fubmarine rocks and ftones, on the fouthern coaft 

 of England, as well as throughout the Adriatic and Medi- 

 terranean feas, and on tlie fhores of France, Spain, and 

 Portugal. Several fronds, from one to three inches high, 

 grow from one central root, fprcading circularly and hori- 

 zontally, each of them rounded at the extremity, either un- 

 divided or lobed, entire at the edges, of a light greenifh- 

 brown. "Wii feeds are thickly lodged, in many brown, arched, 

 tranfverfe, continued lines, making an elegantly ftriped ap- 

 pearance, and refembling the feathers of a turkey-cock. 

 This arrangement of the feeds can fcarcely be thought to 

 contradift the generic charadlcr ; for it appears, in other 

 fpecies, that the expanfion of the frond, after the firft forma- 

 tion, and^xalion, if we may fo expreff it, of ihc feeds, can- 

 not but feparate them, more or Icfs accurately, into p.itches 

 or ftripes. Thefe ftripes are neverthelefs, as we mull allow, 

 more determinate, from the very firll, than in any other 

 known fpecies. The feeds are oval, about two rows in each 

 ilripe. 



2. \5 . Jlabell'iformis. Green Fan Laver. Wulfen Crypt. 

 Aquat. n. n. Decand. Fr. fuppl. 4. Prodr. Fl. Gric. 

 n. 2516. (Conferva flabelliformis ; Dcsfont. Atlant. v. 2. 

 430. Flabellaria Dcsfontainefii ; Lamouroux Ann. du 

 Muf. V. 20. 274. t. 12. f. 4. Tuffillaginc dell' Adriatico ; 

 Gixiann. Adriat. v. i. 25. t. 2j. f. 56.) — Frond fpongy, 



filamentous, flat, fan-fhaped, laciniated and jagged, with a 

 taper bafe — Native of the Adriatic and Ionian feas. Rather 

 taller than the foregoing, of a hght fpongy texture, and 

 uniform green colour, without any ^\(\b\e feeds. The genus 

 of this plant is unqueftionably very doubtful, yet a vague 

 refemblance to U. pavonia, makes us more willing to place 

 it here than any where elfe. With Conferva it ill accords, 

 and few botanifts will follow Ginanni in making it a 

 Tufilago! 



3. U. atomaria. Concentric dotted Laver. Woodw. 

 Tr. of Linn. Soc. v. 3. 53. Engl. Bot. t. 419. — Frond 

 membranous, flat, dilated, palma'e ; fegments linear, flightly 

 branched ; fometimes fringed. — Found waflied up on the 

 Yarmouth coaft, by Mr. Lily Wigg. The root is a fmall, di- 

 lated, downy diflc, bearing a pale olive-brown, thin, wedge- 

 (haped, fpreading frond, four or five inches high, deeply 

 cut into numerous, unequal, irregularly jagged and perfo- 

 rated, oblong or linear, occafionally fringed, fegments ; the 

 whole marked with many tranfverfe concentric ftripes, of a 

 darker hue, full of minute hrovin feds. 



4. U. Itgulata. Laciniated Red Laver. Woodw. Tr. 

 of Linn. Soc. v. 3. 54. Engl. Bot. t. 420 Frond mem- 

 branous, flat, branched ; branches dilated, fomewhat forked, 

 with obtufe finufes ; terminated and fringed with ftrap- 



Ihaped fegments Found by Mr. Wigg, on the Yarmouth 



beach, along with the laft ; but Mr. Woodward met with 

 it, in a growing ftate, on the rocks at Cromer, Norfolk. 

 The root is a fmall callous dillc. Fronds cluftered, from 

 three to fix inches high, of a light rather bright red, mem- 

 branous, but varying in denfity ; their general outline 

 wedge-ftaped, deeply cut into a few principal branches, 

 which fubdivide into others, and are fringed about the 

 bottom with many very narrow fegments, rather blunt at 

 their ends. Seeds extremely minute and abundant, fcattered 

 throughout the whole fubftance, in cloud-like fpots or 

 patches. 



5. U. Lafiuca. Green Laver, or Oyfter-green. Linn. 

 Sp. PL 1632. Hudf. 566. Engl. Bot. t. 155 1. Prodr. 

 Fl. Grsec. n. 2520. Roth. Catal. v. i. 206. (U. marina, 

 laftucx fimihs ; Dill, in Raii Syn. 62. Tremella marina vul- 

 garis, laftucae fimihs ; Dill. Mufc. 42. t. 8. f. i.) — Frond 

 membranous, pellucid, palmate, bright green ; fegments con- 

 trafted below ; dilated upwards, obtufe, plaited — Native 

 of moft of the fhores of Europe, and perhaps other parts of 

 the world, growing on ftones, pebbles, fhells, and the larger 

 fea-weeds, forming annual tufts of thin green leaves, uni- 

 form in colour and texture, but very various in figure and 

 dimenfions ; being fometimes fimplc and undivided, but 

 more frequently palmate, lobed, or proliferous. They 

 always taper downward, and have no ribs nor veins. The 

 very mm\iXe feeds are equally difperfed. — This is the Laver, 

 fo often introduced at fafhionable tables, within a few years 

 paft, being ftewed and fenfoned with lemon juice, wliich 

 moderates its fait bittcrifh flavour and " fea-weed fcent ;" 

 nor is this difh unpleafant, after a fliort trial, to moft palates. 

 We fufpeft it to have been originally contrived with a 

 medical intention, for the benefit of Icrophulous patients, 

 fo numerous, alas ! in the gay circles of the opulent and 

 great. Where laxatives are ufcful or admiffible, nothing 

 can be better applied. 



(}.{]. lubrica. Slippery Laver. Roth. Catal. v. 1 . 204. 



t. 5. f 7. excluding the fynonyms Fronds trifled, oblong, 



convoluted, inflexed, undulated, rugofe, interbranching, very 

 thin and flippery. — Found in ftagnont diti lies of frefli water, 

 in marftiy jiarts of Germany. In tlic fpi ing and beginning 

 of fummer, the plant is fixed to the bottom of the pool or 

 ditch, in denfe, rourdiih, deep-green patches, and is fo cx- 



ceflively 



