1922] Gardner: The Genus Fucus on the Paxiific Coast 49 



fruiting season extends over a much longer period than in most of the 

 other forms. In the summer season, when I have observed them, one 

 may find on the same individual receptacles varying from completely 

 mature, to others just beginning to form, and many more sterile seg- 

 ments. The fronds fork. One branch of the dichotomy metamorphoses 

 directly into a receptacle and the other continues to grow, and it in 

 turn may fork one or more times without fruiting. This makes the 

 mature receptacle appear to be lateral in origin, whereas in reality it 

 originates just as all others do. This seems to be the condition prevail- 

 ing in Thuret's F. platycarpus. Plate 16 in the Etudes Phycologique 

 well illustrates this condition, but illustrates also another condition 

 which does not seem to occur in f. magnijicus, viz., that the suppressed 

 fruiting segments are alternate, whereas in f. magnificus they are 

 secund. I do not know how regularly the condition prevails in F. 

 platycarpus, but this condition is too constantly prevalent in f. mag- 

 nificus to be overlooked as a diagnostic character. 



Fucus evanescens f . stellatus f. nov. 



Plate 53 



Frons distincte flaccida, vulgo contorta, 25-35 cm. alta, dichotoma 

 vel subdichotoma, inferne pallide brunnea, superne luteola, siccata 

 obscure olivaceo-brunnea, stipite et disco radicali comparative parvis; 

 segmentis comparative brevibus, cuneatis, ad apices latioribus, 1.5- 

 2.5 cm. latis, costa superne diminuante. cryptostomatibus paucis et 

 inconspicuis ; reeeptaculis distincte definitsi, complanatis, vel palulum 

 tumidis, decomposite furcatis, vulgo patentibus acuminatisque, 

 3-4.5 cm. longis; conceptaculis numerosis, conspicuis. 



Growing on boulders, logs, etc., in the lower littoral belt. Sack- 

 man's Point, near Tracyton, Kitsap County, Washington. 



Type, Gardner, no. 2202 (Herb. Univ. Calif., no. 201144), May, 

 1910. Fucus evanescent, Tilden, Amer. Alg. (Exsicc), no. 235, same 

 locality as above. 



Tilden 's no. 235 seems to belong here, although the specimen in 

 Professor Setchell's copy of her American Algae is only a fragment 

 and just beginning to produce receptacles. 



The distinguishing character of this form is the decompositely 

 furcate receptacles, often widely divergent. As many as eight 

 divergent apices have been observed with a common base. The fronds 

 are decidedly flaccid and dissolve rather readily in fresh water after 

 being dried. 



