1922] Gardner: The Genus Fucus on the Pacific Coast 23 



Forma luxurians is closely related to forma typicus. The two 

 forms often grow intermingled, but may readily be distinguished by 

 differences in size and color, forma luxurians being much more robust, 

 and of a lighter brownish or yellowish color in the upper parts, par- 

 ticularly the receptacles. The southern limit of the form, as of all 

 forms of Fucus so far as is at present known, is Oil Port, San Luis 

 Obispo County, California. The northern limit has not yet been deter- 

 mined, but it probably extends as far north as Cape Flattery, Wash- 

 ington, where there is an intermingling of several forms whose limits 

 have not yet been determined. It merges into forma elongatus from 

 Coos Bay, Oregon, which I have segregated, as is illustrated on plate 9. 



The plants persist for several years, are in fullest fruit in early 

 summer, although some receptacles may be found at any season of the 

 year. Always a portion of the segments resulting from forking remains 

 sterile. These continue to grow and branch, forming segments for the 

 next year's receptacles, while the other segments fruit and disintegrate, 

 leaving the midrib of the segment as a pointed projection. The plants 

 do not seem to proliferate. Many of the alae split obliquely to the 

 midrib, giving them a serrate appearance. Plants growing at Pacific 

 Grove, California, which I have referred to this form, are subject to 

 this habit quite generally. I have noticed also that in this locality the 

 plants have a decided tendency, toward the end of the growing season 

 of the receptacles, to establish several meristematic regions on the 

 ends of the receptacles, some of which produce quite prominent and 

 pointed projections with a tendency to becoming vegetative, as many as 

 ten having been observed on a single receptacle with a common wide 

 base. 



Fucus furcatus f. reflexus f . nov. 



Plates 11, 11a, and 12 



Frondes foliaceae, subcartilaginosae, 30-45 cm. altae, regulariter 

 dichotomae, obscure olivaceo-virides vel obscure olivaceo-castaneae, 

 angulis saepissime latissimis rotundatisque ; segmentis inf erne cuneatis, 

 terminalia saepe obovatis, 8-25 mm. latis, apicibus rotundatis, puncto 

 crescente paululum depresso, costa angusta distincta, superne paullo 

 evanida, caecostomatibus numero variabilibus, 50-150 in quoquo cm. 

 quadrato; receptaculis manifeste definitis, substipitatis, complanatis, 

 ellipsoideis, integris vel bifidis, late patentibus; conceptaculis parvis 

 numerosisque. 



Growing on boulders in the lower littoral belt. Point Defiance, 

 Tacoma, Washington. 



Type, Gardner, no. 2190 (Herb. Univ. Calif., no. 201145), May, 

 1910. 



