Ser. Melanospeeme^. Pam. Laminariea. 



Plate CCXXIII. 



LAMINARIA DIGITATA, Lamour. 



Gen. Char. Frond stipitate, coriaceous or membranaceous, flat, undivided 

 or irregularly cleft, ribless. Fructification ; cloudy spots of spores, 

 imbedded in the thickened surface of some part of the frond. Lami- 

 naria (Lamour.), — from lamina, a thin plate, in allusion to the flat 

 frond. 



Laminaria digitata ; stem long, woody, cylindrical, gradually tapering 

 and somewhat compressed upwards, expanding into a leathery, 

 roundish-oblong frond, deeply cleft into many linear segments. 



Laminaria digitata, Lamour. Fss. p. 22. Lyngb. Hyd. Ban. p. 20. Ag. Sp. 

 Jig. vol. i. p. 112. Ag. Syst. p. 270. Grev. Alg. Brit. p. 27. Book. Br. II. vol. 

 ii. p. 271. Harv. in Mack. Fl. Rib. part 3. p. 171. Harv. Man. p. 23. Wyatt, 

 Alg. Banm. No. 156. Endl. 3rd. Suppl. p. 27. Post, and Rupr. t. 12. /. Ag. 

 Sp. Alg. vol. i. p. 134. 



Laminaria stenoloba, Be Lap. Terr. Neuv. p. 55. 



Hafgygia digitata, Kiitz. Phyc. Gen. p. 346. t. 30. and 31. 



Fucus digitatus, Linn. Mant. p. 134. Fl. Ban. t. 392. Stack, Ner. Brit. p. 5. t. 

 3. Esper,p. 99. t. 48, 49. Huds. Fl. Angl. p. 579. Ligldf. Fl. Scot. p. 935. 

 With. 4. p. 98. Linn. Trans. 3. p. 152. Turn. Syu. p. 207. Turn. Hist. t. 162. 

 E.Bot.t. 2274. 



Fucus hyperboreus, Ghrnn. Fl. Norv. 1. p. 34. t. 3. 



Hab. On ropks in the sea, beyond the reach of the tide, extending to the 



depth of about fifteen fathoms. Perennial. Winter. Abundant 



on the shores of the British Islands. 



Geogr. Distr. The ley sea, and Northern Atlantic, from Norway to Spain, 

 and from Greenland to the shores of Massachusetts {at least). Kamts- 

 chatka. 



Descr. Root, a conical mass composed of numerous, stout, branching fibres, each 

 of whose branches ends in a flattened disc which takes a strong hold of the 

 rocky bottom. Stem from two to six feet long, cylindrical, solid, in large 

 specimens upwards of an inch in diameter near the base, gradually tapering 

 upwards and becoming compressed towards the summit, where it passes into 

 the base of the frond. Frond from one to five feet long, and from one to 

 three feet in breadth, deeply cleft from the apex nearly to the base into an 

 uncertain number of linear, strap-shaped, acute or obtuse segments. Fruc- 

 tification dark coloured, cloud-like patches, seen on old fronds, consist ing 

 of a stratum of innumerable, minute, angular, dark-coloured spores, concealed 

 beneath the surface cells. Substance in the stem woody, but flexible, hard 

 and horny when dry ; in the frond, leathery. Structure cellular; the cells 

 of the central portion of stem and frond ver\ minute ; those of the periphery 

 larger; in the frond quadrate, with spherical air-cells at intervals. Culoui\ 

 a line clear olive, becoming darker in age. 



VOL. II. 



