50 University of California Publications in Botany [ VoL - ]0 



Fucus evanescens f. longifructus S. and G. 



Plate 54 



Frond with short stipe and firm holdfast, somewhat caulescent 

 below, foliaceous 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 eomplanate, not definitely delimited, 2-2.5 cm. wide, one to 

 three times forked, with the divisions long, linear or sometimes re- 

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

 scattered. 



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

 Alaska. 



Type, Setchell and Lawson, no. 5151 (Herb. Univ. Calif., no. 

 99110), Orca, Alaska. Collins, Holden, and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. 928; Setchell and Lawson, no. 5186 (Herb. Univ. Calif., 

 no. 99109), Juneau, Alaska. 



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



A cotype specimen of this very distinct form is illustrated on 

 plate 54, and it features the distinguishing characteristics very well. 

 It is unlike all other forms in the extremely long, linear-lanceolate, 

 regular eomplanate receptacles, frequently spreading or recurved at 

 the apices. In external appearance it approaches F. furcatus f. 

 rigidus, but that form has an abundance of caecostomata, the recep- 

 tacles usually more decompositely furcate, and it is more cartilaginous. 

 No. 5186 from Juneau is placed here with some doubts. If it should 

 be placed here, it should be considered at the lower limit of variation 

 in size. 



Fucus evanescens f. cornutus Kjellm. 

 Plate 55 



"f. segmentis inferioribus ad costas demum reductis, superioribus 

 linearibus, subcoriaceis, angustis, 3-4 mm. latis, costa valida, at parum 

 prominente; receptaeulis sublimitatis, usque 4 cm. longis, 5-10 mm. 

 crassis, turgidis, decomposito-furcatis, ramis inferioribus subcylin- 

 dricis, summis subcoriaceis; scaphidiis magnis." 



"Beringon. ymnig; tillsamman med de bada foregaende formerna, 

 bildande en individrik Fucus- f o rmation ; med receptakler. " 



Kjellman, Om Beringh. Algflora, 1889, p. 34. 



Fronds subcoriaceous, 20-30 cm. high, regularly dichotomous, dark 

 olive green to dark olive brown ; segments strict, linear or very slightly 

 cuneate in the narrower specimens, 5-8 mm. wide, apices truncate, 

 midrib well developed, prominent, very slightly evanescent above, 

 alae narrow, cryptostomata very sparse, small; receptacles distinctly 



