680 University of California Publications in Botany L V ° L - S 



3. Fucus edentatus f. costatus Gardner 



Fronds slender, subcoriaceous, 15-25 cm. high, regularly dicho- 

 tomous, yellowish brown, segments distinctly linear, relatively long, 

 reduced in width above each forking, widest 5-8 mm., terminal 2-4 

 mm., midrib highly developed, percurrent, alae narrow and mem- 

 branaceous, cryptostomata sparse, prominent; receptacles definitely 

 delimited, simply or mostly bifid, 20-35 cm. long, apices acute; con- 

 ceptacles moderately abundant and conspicuous. 



Growing on rocks in the lower third of the littoral belt. Lower 

 Puget Sound region, Washington. 



Gardner, Genus Fucus, 1922, p. 30, pis. 23, 24. Fucus evanescens 

 f. august us, Collins, Holden and Setchell, Phyc. Bor.-Amer. (Exsicc), 

 no. 926; Setchell and Gardner, Alg. N.W. Amer., 1903, p. 284. 



The plants distributed in the Phycotheca Boreali-Americana as 

 no. 926 are from the type locality, but were taken from the upper 

 limit of the belt of distribution when the tide was well in ; they are 

 considerably battered and worn away, and thus cannot be said to be 

 in typical condition. 



This form resembles closely F. evanescens f. angustus Kjellm. in 

 width of fronds, and was so referred as is cited above. Subsequent 

 to the foregoing publications, material of the species, collected and 

 determined by Kjellman on the Vega expedition, has been received at 

 the Herbarium of the University of California (no. 132699). The lack 

 of a prominent percurrent midrib, almost complete absence of crypto- 

 stomata, and especially the very small receptacles of Kjellman 's 

 material, indicate unmistakably that our plant is of a different lineage. 



4. Fucus edentatus f. acutus Gardner 



Fronds 9-15 cm. high, arising from a relatively broad, flat hold- 

 fast, dichotomous, angles acute, olive green, black on drying ; segments 

 linear, 3-4 mm. wide, apices truncate, midrib very prominent, percur- 

 rent, alae relatively narrow, persistent, cryptostomata sparse; recep- 

 tacles single or deeply bifurcate, tapering at both ends, 2-2.5 cm. long. 



Growing on sandstone in the middle littoral belt. Bellingham 

 ( Fairhaven ) , Washington. 



Gardner, Genus Fucus, 1922 p. 31, pi. 25. Fucus inflatus f. 

 linearis, Setchell and Gardner, Alg. N.W. Amer., 1903, p. 280. 



The very dark color on drying, the absence of caecostomata, and 

 the sparseness of cryptostomata in this form seem amply sufficient to 



