1922] Gardner: The Genus Fucus on the Pacific Coast 35 



may be readily recognized by its light yellowish color, its mostly 

 inflated receptacles, and by its moderately narrow, long, membra- 

 naceous fronds. 



Fucus membranaceus f . limitatus f . nov 

 Plate 32 



Frondes manifeste membranaceae, 22-32 cm. altae, dichotomae, 

 pallide luteolae. siccatae obscure brunneae, stipite et disco radicali 

 fragilibus; segmentis strictis, vulgo cuneatis, plerumque ad axillas 

 latioribus. 12-20 mm. latis, lobis terminalibus rotundatis, puncto cres- 

 cente paullo depresso, costa non prominente, alis tenuibus, crypto- 

 stomatibus sparsissimis et non conspieuis; receptaculis vulgo inflatis, 

 bifidis. apicibus acuminatis vulgo divergentibus magnitudine valde 

 variabilibus. usque ad 5 cm. longis, 2 cm. latis; conceptaculis sparsis 

 non prominentibus. 



Growing on rocks, logs, etc., in sheltered localities in the upper 

 third of the littoral belt. Point Defiance, Tacoma, Washington. 



Type. Gardner, no. 2189 (Herb. Univ. Calif., no. 201160), May, 

 1910. 



It is not easy to delineate the distinctive characters of this form 

 associating it with the membranaceus group, rather than with the 

 evanescens group. In many specimens the midrib is quite indistinct. 

 The cryptostomata characters are quite as much of the one group as of 

 the other. I am placing it provisionally with the former group largely 

 on account of the predominance of inflated receptacles, on the mem- 

 branaceous character of the fronds, and on the color. 



Two forms of Fucus were found growing at Point Defiance, rep- 

 resenting an interesting case in distribution. Forma limitatus occupied 

 for the most part the extreme upper portion of the littoral belt, and 

 grew on logs and boulders. F. furcatus f. reflexus grew on boulders 

 and occupied the lower third, with an occasional plant of either form 

 invading the central part. 



Fucus membranaceus f. latissimus f. nov. 

 Plates 33 and 34 

 Frondes foliaceae, membranaceae, crispatae, dichotomae, 22-35 cm. 

 altae, inferne obscure olivo-virides, superne fulvae disco radicali parvo, 

 stipite eomplanato; segmentis superne paululum ovatis, inferne 

 angustioribus euneatisque, subterminalibus 4r-6 cm. latis, costa com- 

 parative angusta percursa. alis tenuibus, membranaceis,.saepe inflatis, 

 marginibus undulatis apicibus rotundatis et levibus, puncto cres- 

 cente inconspicuo, cryptostomatibus 15-20 in quoquo cm. quadrato, 

 paraphyses midtas protrusas producentibus, siccatis prominentibus; 

 receptaculis sparsis, complanatis, indistincte definitis, basi latioribus, 

 bi-tri-fureatis. 



