592 



FUCACZAE. 



1. 5. natans. 



2. .?. fluitans. 



2. Turbinaria tricostata Barton, Trans. Linn. Soc. Bot. II. 3: 21S. pi. oi. f. 3. 

 1891. 



On surge-swept rocks, low-littoral. New Providence. South Cat Cay, and Gun 

 Cay: Bermuda to Guadeloupe. Type from Guadeloupe i ': \ . 

 Apparently intergrading with T. turtinata. 



3. SAE.GASSUM Ag. >p. Alg. 1:1. 1820. 



Floating and sterile. 



Leaves very narrowly linear or linear-aliform, mostly 12 mm. broad, the teeth 

 aculeate-acuminate ; vesicles commonly aristate-apicu- 

 late. 

 Leaves linear or linear-lanceolate, mostly 21 mm. broad, 



the teeth triangular-acuminate : s muticous. 



Normally attached (nos. 3 and 10 sometimes more or less 



pelagic i . 

 Leaves mostly narrowly linear, usually 7-50 times as 



long as maximum width. 



Leaves rather rigid, cryptostomata usually somewhat 

 obscure, pedicels of the muticous vesicles com- 

 monly shorter than the vesicles themseb 

 receptacles in rather short axillary clusters. 

 Leaves serrate-dent.-ue. the c-'sra prominent and 

 often dentate : vesicles commonly large and 



crowded : stems often 12 m. long and subsimple. 3. S. ptcropleuron. 



Leaves subentire, the costa not dentate : vesir-: - 



usually scattered: stems m< :--.- 2-10 dm. long. 4. S.cymogum. 



Leaves thinly membranous, cryptostomata obvious, ped- 

 icels of the often appendaged usually scattered 

 vesicles commonly of about the same length as 

 the vesicles themsel' tinally elon- 



gate and often forming a kind of] -erminal 



panicle through reduction of the le;v - 

 Leaves ovate, ovate-elliptic, oblong, lanceolate, or rather 



I 



Cryptostbmata elevated, very large and conspicuous 

 r> mm. in maximum diam. often elliptic, 

 in a single series on either side of the costa ; 

 leaves linear or lanceolate. 



Cryptostomata smaller, sometimes obscure or wanting. 

 Cryptostomata obvious. 



Receptacles mostly in a rather dense terminal 

 panicle : leaves lanceolate or linear-oblong, 

 rather obscurely and obtusely dentate or 

 margins merely sinuate, cryptostomata in 

 almost a single - - n either side of the 



sta : "--ioles sometirc- 



Receptacles obviously lateral and axillary, 

 elongate or contracted : cryptostomata in 

 more than a single 



Leaves linear or linear-oblong, mostly 4 8 

 times as long as broad, sharply serrate- 

 dentate: vesicles mostly ellipsoid or ob- 

 ovoid. often subapicnlate : receptacles 



contracted, oft- 1 :. -dentate. 8. B. vulgaref 



Leaves ovate, elliptic, oblong, or lanceolate, 

 mostly 2 i times - long as broad, com- 

 monly crisped, variously aculeate-dentate 

 or Hex-' - - r sub- 



globose, muticous: receptacles sometimes 

 - -'rasionally with a few sub- 



spinescent rr 



Cryptostomata obscure or wanting: leaves cori- 

 aceous, oblong-elliptic, spinescent-dentate or 

 entire or sub-entire : receptacles more or less 

 spinescent-dentate. 



1. Sargassum natans L.j Meyen, Wiegm. Arch. Xaturgesch. 4 : : ISo. 1*35. 



atans L. Sp. PI. 1160. 175 

 F'/c-us Sargasso S. G. Gmel. Hist. Fuc. 92. 17^-. 



'"icciferus Turn. Hist. Fuc. 1: 105. pi. 47. 1808. 

 Sargassum bacciferum A?. >r. Alg. 1: 6. 1820. 



The chief ingredient of the " Sargasso Sea " found floating or washed ashore 

 throughout the archipelago. 



.V. platycarpum. 



7. .S'. lendiyrum. 



9. S polyceratium. 



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