HOW TO KNOW THE SEAWEEDS 



99a Apex of pneumatocyst with four short, flattened branches which 

 are four to five times dichotomous. Fig. 133. .NeTeocystis luetkeana 



Fig. 133. Nereocystis luetkeana (Martens) Pos- 

 tals & Ruprecht 



A pnaumatocyst showing tha bulbous, tar, 

 minal swelling and four dichotomous, blade- 

 bearing branches, X 0.2. This is a giant kelp 

 which grows in great beds from rocks 30 to 

 50 feet below the surface, sending up the 

 pneumatocysts and blades which float out at 

 the surface. Common along the Pacific Coast 

 except in southernmost California. 



Figure 1 33 



99b Apex of pneumatocyst with a single large antler-like, forked 

 branch. Fig. 134 Pelagophycus porra 



Fig. 134. Pelagophycus porra (Leman) Setchell 



Habit of an entire plant, X 0.04, showing the holdfast, long, ris- 

 ing stipe and blade-bearing terminal pneumatocyst. This is probably 

 our most spectacular large Pacific coast kelp. It occupies habitats 

 outside the Macrocystis beds in somewhat deeper water and is avoided 

 by the commercial kelp cutters. Its range extends from Point Concep- 

 tion, CaUfornia southward into Mexico. 



102 



