Ser. Melanospeiime^. Fam. Fucaceix. 



Plate CX. 

 SARGASSUM RAOULII, Hook p. et Ilarv. 



Gen. Char. Eoot scutate. Frond pinnately decompound, with distinct stem, 

 branches, leaves, vesicles, and receptacles. Vesicles stipitate, supra- 

 axillary, simple, most frequently mucronate or leaf-bearing. JRecep- 

 tacles pod-like, torulose or moniliform, axillary. Scaphidia dioecious. 

 Spores obovoid. — Sargassum [Ag.), from the '&\)^ms\\ sargazo, a name 

 given by navigators to floating seaweed. 



Radix scidata. Frons pinuatim decomposita, caule proprio, ramis, foliis, 

 vesicuUs, receptacuUsque doiiata. Vesiculce dipitatcs, supra-axillares, simpli- 

 ces, saplssime tnucronatce v. fol'dfercB. Receptacula silujU(sformia, torulosa v. 

 nodulosa, axillaria. Scaphidia dioica. Sjmrce obovoidece. 



Sargassum Raoidii ; stem very long, slender, smooth, strongly compressed, 

 two-edged, angularly bent, alternately decompound ; branches similar ; 

 leaves alternate, distichous, vertical, repeatedly dichotomous ; the 

 segments very narrow, linear, piano-compressed, nerveless, sparingly 

 glandular; vesicles spherical, mucronulate, at length muticous; re- 

 ceptacles smooth, submoniliform, racemoso-paniculate. 



S. Eaoulii ; caule longlssimo gracili Icevi arete compre&so aiicipiti angidatim 

 fiexuosa alterne decomposito ; ramis similihm ; foliis distichis verticalibus 

 pluries dicJiotomis fastigiatis ; laciuiis angustissimis linearihus plano-compressis 

 enerviis parce glandulosis ; vesiculis sphcericis setaceo-mucronulatis demuvi 

 muticis ; receptaculis Icevibus nodulosis racemoso-paniculaiis. 



Sargassum Eaoulii, Rook. Jil. et Harv. in Hook. Lond. Journ. v. 4. p. 523. 

 Fl. N. Zeal. v. 2. p. 212. /. Ag. Sp. Alg. v. 1. p. 289. Harv. Alg. 

 Austr. Exsic. n. 24. Harv. in Hook. Fl. Tasm. p. 282. 



Hab. Shores of Tasmania. Sandy Bay, Br. Li/all and Br. HooJcer. South 

 Port, Mr. C. Stuart. Abundant at Georgetown, Mr. Gmin, W. H. IL 

 Port Arthur, r.^.i?. 



Geogk. Distr. Tasmania. New Zealand, Raoid. 



Descr. Root discoid. Frond three to six or eight feet long or more, much 

 branched ; the branches either developed alternately on a lengthened stent, 

 or many starting near the root from a short primary stem, and constituting 

 so many secondary stems. Both stem and branches are slender, from half a 

 line to a line in breadth, strongly compressed and the broader two-edged, 

 angularly bent at short intervals, gradually attenuated upwards and passing 

 at the extremity into almost filiform prolongations. The lower part of the 

 branch, often for a foot or more, is denuded of leaves, and armed at intervals 

 of |-1 inch with the spine-like remains of old petioles. The leaves are dib- 



