19-5] SetcheJI-Gardner: Melanophyceae 669 



6. Fucus furcatus f. variabilis Gardner 



Fronds caulescent, foliaceous above, 25-40 cm. high, subcartilagin- 

 ous, dichotoraous or in part subseciind, dark olive green to olive brown, 

 black on drying, midrib and receptacles yellowish ; segments linear 

 to moderately cuneate, 2-3.5 cm. wide, usually reduced in width above 

 each forking, midrib well developed, percurrent, caecostomata vary- 

 ing from few up to 75 per sq. cm. ; receptacles very variable in shape 

 and size, definitely delimited, swollen and mucilaginous or complanate, 

 simple and blunt or bi- tri-furcate and acuminate. 



Growing on rock ledges in quiet bays in the middle of the littoral 

 belt. Sitka, Alaska. 



Gardner, Genus Fucus, 1922, p. 26, pis. 16, 17. 



A close relationship seems to exist between this form of F. furcatus 

 and F. evanescens f. magnificus. The color, caecostomata characters, 

 and the rigid, more or less cartilaginous consistency of the fronds are 

 characters that belong to the furcatus group. The width of segments 

 and particularly the fruiting habit (see under F. evanescens f. 

 magnificus) are very similar to those of that form. The caecostomata 

 vary much in number. In some specimens they are practically absent, 

 while in others there may be seventy-five or perhaps more to the square 

 centimeter. They are mostly large, deep-seated, and inconspicuous 

 on drying, except by transmitted light. Specimens with but a few 

 caecostomata usually have a few small cryptostomata. 



7. Fucus furcatus f. refiexus Gardner 



Fronds foliaceous, subcartilaginous, 30-45 cm. high, regularly 

 dichotomous, dark olive green to dark olive brown, angles mostly very 

 broad and rounded ; segments cuneate below, terminal often obovoid, 

 8-25 mm. wide, apices rounded, growing point only slightly depressed, 

 midrib narrow but distinct, slightly evanescent above, caecostomata 

 very variable in number, 50-150 per sq. cm. ; receptacles distinctly 

 delimited, substipitate, complanate, ellipsoidal, entire or bifid, wide- 

 spreading; conceptacles small and numerous. 



Growing on boulders in the lower littoral belt. Point Defiance, 

 Tacoma, Washington. 



Gardner, Genus Fucus, 1922, p. 23, pis, 11, Ha, and 12. 



The consistency of this form is somewhat like that of the evanescens 

 group, the tissues being more delicate and soft than those of the typical 



