668 University of California Publications in Botany [Vol.8 



4. Fucus furcatus f. rigidus Gardner 



Plate 100 



Fronds robust, rigid, cartilaginous, 30-45 cm. high, dichotomous or 

 subsecund, dark olive green, black on drying, midrib and receptacles 

 olive green below, olive brown and yellowish above, angles mostly 

 rounded; segments linear or slightly cuneate, strict, 1.5-3 cm. wide, 

 apices truncate, midrib prominent, caecostomata, 60-100 per sq. cm. ; 

 receptacles not definitely delimited, complanate, linear, apices acumin- 

 ate, bi- tri-f urcate, 10-20 mm. wide, 5-8 cm. long ; conceptacles large, 

 covering a cuneate area extending down the midrib from the receptacle. 



Growing on boulders in the lower littoral belt. Port Townsend 

 and the west coast of Whidbey Island, Washington. 



Gardner, Genus Fucus, 1922, p. 24, pi. 13. 



According to our conception of this form, its phylogenetic position 

 is between forma latifrons and forma luxurians. From the former 

 it differs in having a more rigid cartilaginous structure, in having 

 narrower and more strict segments, and in having longer and narrower 

 receptacles. From the latter it differs in having more strict and more 

 nearly linear segments and longer and narrower receptacles. 



5. Fucus furcatus f . contortus Gardner 



Fronds 20-30 cm. high, caulescent below, foliaceous above, robust, 

 cartilaginous, much contorted, dichotomous or subdichotomous, olive 

 green below, yellowish above, dark olive brown on drying; segments 

 cuneate below, margins crisped, linear above, reduced in width above 

 each forking, 2-2.5 cm. wide, apices rounded, growing depression 

 slight, midrib prominent, caecostomata 250-300 per sq. cm., minutely 

 papillate on drying; receptacles complanate, 4-7 cm. long, not 

 distinctly delimited. 



Growing in quiet water on boulders in the lower littoral belt. Near 

 Bellingham, Washington. 



Gardner, Genus Fucus, 1922, p. 25, pi. 15. 



This form seems to be quite distinct from all others. Its color, its 

 rigid, cartilaginous consistency, its relatively wide fronds, its large 

 number of caecostomata, its contorted and crisped habit of growth 

 are characters not found combined in any other known form. The 

 plants were found growing in great profusion, in good vegetative 

 condition in midsummer. The fruiting season apparently is in the 

 winter, as only a few well developed receptacles could be found. 



