704 University of California Publications in Botany [Vol. 8 



Hesperophycus Harveyanus (Dec'ne) S. and G. 



Frond 2-4 dm. high, dichotomous, usually one of the dichotomies 

 outgrowing the other, forming several main axes, some of the laterals 

 with several branches close together becoming flabellate; color dark 

 olive green, or yellowish brown when in exposed situations ; segments 

 5-10 mm. wide, with a row of cryptostomata extending longitudinally 

 on either side of the midrib, having an abundance of extruding para- 

 phrases ; receptacles simple but in part bifurcate, 1.5-3 cm. long, 

 cylindrical to ellipsoidal. 



Growing on rocks in a restricted belt a few feet below high-tide 

 limit. The present known range is from Monterey Bay to Lower 

 California (Ensenada). 



Setchell and Gardner, in Gardner, Nuclear Extrusion, 1910, p. 127, 

 pi. 16, figs. 8-10, New Fucaceae, 1913, pp. 317-320, pis. 36-37 ; Collins, 

 Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), no. CXII. Fucus 

 Harveyanus Dec'ne, Voyage Venus, 1864, p. 9, Altas, 1846. pi. 4. 

 Fucus ceranoides f. Harveyanus Tilden, Amer. Alg. (Exsicc), no. 339. 



family 25. SARGASSACEAE de-toni (lim. mut.) 



Fronds differentiated into holdfast, stipe and more or less indis- 

 tinguishable from it the main rhachis of the frond which bears the 

 variously modified or differentiated branches arising on all sides of 

 the rhachis, and usually far surpassing it in length; stipe and main 

 rhachis perennial, the growing region at the apex of the rhachis some- 

 what obscure, primary branches fruiting, then disintegrating back to 

 the rhachis, leaving scars on the constantly elongating axis; oogonia 

 usually few and large ; receptacles small, cylindrical, or slightly 

 complanate, terminal or subterminal. 



De-Toni, Syst. Uebers. Fucoid., 1891, p. 174. 



Key to the Genera 



1. Vesicles absent in our species 69. Blossevillea (p. 705) 



1. Vesicles present 2 



2. Vesicles single 73. Sargassum (p. 711) 



2. Vesicles seriate 3 



3. Stipe short in our species, merging into the hapteres . . . . 70. Cystophyllum (p. 706) 



3. Stipe long, persistent 4 



4. Stipe decidedly angular 72. Cystoseira (p. 70S) 



4. Stipe terete, more or less geniculate 71. Halidrys (p. 707) 



