HOW TO KNOW THE SEAWEEDS 



chell) Setchell & Gardner is probably the most widespread. Smith's 

 (1944) illustrations of several California species are helpful to students 

 in learning to recognize these polymorphic gigartinas. The only avail- 

 able monographic treatment is Setchell and Gardner 1933, (Univ. Calif. 

 Publ. Bot. 17 (10):255-340) which contains numerous photographs. 



Other species of this genus are treated in this key under steps 

 151a and 235a. 



168b Flat surfaces of branches smooth, 



169 



169a Thallus normally with determinate secondary pinnate branches 



from the primary dichotomous branches. Fig. 211 



Zanardinula (in part) 



Fig. 211. Zanardinula cornea (Okamura) 

 Dawson 



A small upper portion of a plani aboui 

 20 cm. high to show the dichotomous 

 primary branching and determinate sec- 

 ondary pinnate branchlets, X 1.1. This is 

 a Pacific Coast genus of which one or 

 more of our half dozen species may be 

 found at almost any rocky intertidal sta- 

 tion from southern California to Washing- 

 ton. Z. cornea, found from central Oregon 

 southward, is one of three species which 

 will key out here because of the dicho- 

 tomous primary branching. The others will 

 not give the impression of being dicho- 

 tomous and will key out under step 188a. 



Figure 21 1 



169b Thallus normally without determinate secondary pinnate branches 

 170 



160 



