638 University of California Publications in Botany [Vol. 8 



It was collected on St. Paul Island of the Pribiloff Group. Yendo has 

 (1919, p. 88) with justice said that '*it is to be questioned as to how 

 Setchell comprehended A. praelonga Kjellm. " Setchell, finally, 

 has restricted his view to a plant closely resembling^ Kjellman's figure 

 and type specimen, both young plants. 



3. Alaria tenuifolia Setchell 



Stipe 16-60 cm. in length, cylindrical or nearly so only at the very 

 base, much flattened above, slender and flexible ; rhachis more or less 

 elongated, flattened, with the sporophylls at first remote in young 

 plants, later crowded ; blade 10-15 dm. long, 10-35 cm. wide, broadly 

 to narrowly cuneate at the base, very thin, collapsing when withdrawn 

 from the water, with plentiful cryptostomata of small size ; midrib 

 narrow to fairly broad, oblong in cross-section ; sporophylls from 

 narrowly to broadly lanceolate and cuneate at the base, varying to 

 broadly ovate or oblong and distinctly cordate at the base, sessile or 

 with more or less pronounced stipes. 



Not uncommon, from the Bering Sea to Puget Sound, Washington. 



Setchell, in Collins, Holden and Setchell, Phyc. Bor.-Amer. 

 (Exsicc), no. XLV, Kelps of the U. S. and Alaska, 1912a, p. 162, 

 Critical notes on the Laminariaceae, 1908^, p. 12 ; Setchell and Gard- 

 ner, Alg. N.W. Amer., 1903, p. 272. Alaria Pylaii Yendo, Monogr., 

 1919, p. 97, pi. 7 (at least in last part, but not Agarum Pylaii Bory.). 



Two well-marked forms have been noted as follows: 



Alaria tenuifolia f. typica Setchell 



Stipe of moderate length, 10-15 cm. long; blade comparatively 

 narrow, 8-15 cm. in width and cuneate at the base ; midrib not 

 noticeably broad; sporophylls narrowly to broadly lanceolate with 

 cuneate base and short stalks. 



On rocks and stone at low water mark. Amaknak Island, Bay of 

 Unalaska, Alaska, 



Setchell, in Setchell and Gardner, Alg. of N.W. Amer., 1903, pp. 

 273-274, pi. 22. 



