1925] Setch ell-Gardner: Mclanophyceae 689 



8. Fucus evanescens f. flabellatus Gardner 



Fronds 15-25 cm. high, subcoriaceous, subdichotomous or, in part, 

 secund, light brown to yellowish brown, holdfast small, stipe small, 

 2-3 cm. long ; segments linear to very slightly cuneate, 10-15 mm. wide, 

 strict, apices rounded, slightly truncate, alae relatively thin, midrib 

 slightly reduced below the receptacles, cryptostomata few, small, 

 inconspicuous ; receptacles fusiform, 2-3.5 cm. long, simple to bifurcate, 

 not definitely delimited. 



Growing on sandstone ledges in the middle of the littoral belt. 

 Bellingham, Washington. 



Gardner, Genus Fucus, 1922, p. 44, pi. 43. 



The majority of the plants seemed scarcely mature in July, when 

 they were collected, but enough of them were selected that appeared 

 mature to be fairly certain that the measurements given for the recep- 

 tacles are sufficiently accurate. The distinguishing character of the 

 form is the pronounced fan shape of the whole frond when spread out, 

 and particularly of groups of segments, due to the secund method of 

 branching. 



The cryptostomata are relatively few and inconspicuous, and there 

 is approximately the same number of caecostomata ; thus in this char- 

 acter this form is on the border line between F. evanescens and 

 F. furcatus. Probably the tendency is in the direction of the degenera- 

 tion of these organs. The other characters, however, seem sufficiently 

 well represented to ally it with F. evanescens. 



9. Fucus evanescens f. longifructus S. and G. 



Frond with short stipe and firm holdfast, somewhat caulescent 

 below, f oliaceous above, up to 45 cm. high, dark olive brown ; segments 

 long and narrow, strict, 1-2 cm. wide, midrib moderately conspicuous, 

 slightly evanescent, cryptostomata absent or very sparse; receptacles 

 usually complanate, not definitely delimited, 2-2.5 cm. wide, 1-3 times 

 forked, with the divisions long, linear or sometimes recurved and 

 pointed, up to 22 cm. long ; conceptacles very large and scattered. 



Growing on stones in the upper littoral belt. Orca to Juneau, 

 Alaska. 



Setchell and Gardner, Alg. N.W. Amer., 1903, p. 283; Gardner, 

 Genus Fucus, 1922, p. 50, pi. 54. 



