40 University of California Publications in Botany [Vol. 10 



Type, Gardner, no. 2791 (Herb. Univ. Calif., no. 201217), May, 

 1914. 



Forma ecostatus is quite abundant at various localities from the 

 mouth of Coos Bay up to its headwaters where several streams of fresh 

 water flow in. This form seems to be definitely fixed, and does not 

 appear to grade into any of the forms that are found growing outside 

 of the bay. More investigation, however, may show that it is only a 

 depauperate form of some definite species; on the other hand, it may 

 prove to be a distinct species. It varies considerably in size and width 

 of the fronds. The receptacles, though mostly pointed, are at times 

 wide and blunt ; at least there are specimens growing in the same 

 habitat which have the same general characters but differ only in 

 the character of the receptacles, and in such cases the segments are 

 generally wider. They are connected, however, by almost impercept- 

 ible gradations. The size of the plants may be somewhat influenced 

 by the substratum, mostly wood and soft sandstone, neither of which 

 is suited to holding plants for a very great length of time. They 

 usually do not persist in such localities beyond a single fruiting period. 

 If the vanishing of the midrib is to be considered as having any 

 diagnostic value, this form eminently belongs with the evanescens 

 group. The midrib in some specimens is scarcely discernible in any 

 part of the frond, and in all it vanishes in the terminal segments, 

 t 



Fucus evanescens f. oregonensis f. nov. 

 Plate 40 



Frons distincte caulescens, 15-20 cm. alta, subcoriacea, inferne 

 dichotoma, superne subsecunda, luteola; segmentis angustis, sublinear- 

 ibus vel paululum cuneatis, 4—7 mm. latis, flaccidis, levibus, costa 

 angusta inferne evidente, superne parum evanida, cryptostomatibus 

 parvis, inconspieuis. 20-25 in quoquo cm. quadrato; receptaculis 

 tumidis, distincte definitis, quam segmentis ea gerentibus multo latior- 

 ibus, integris aut bifidis, late fusiformibus, apicibus, valde obtusis: con- 

 ceptaculis paidulum conspicuis. 



Growing on floats, piles, stones, etc., in the middle and upper lit- 

 toral belts. East side of Coos Bay, opposite North Bend. Oregon. 



Type, Gardner, no. 2786 (Herb. Univ. Calif., no. 201197), May, 

 1914. 



This form seems decidedly distinct from all other forms previously 

 described. Judging from its size, color, character of the midrib and its 

 general consistency, its nearest relatives are to be found in the evan- 

 escens group, and close to forma flabellatus of this paper. The plants 



