1917 



Muenscherj Key to Phaeophyceae 



277 



almost filamentous^ with one or more small vesicles or air bladders near 

 the tip; eonceptacles just below the vesicles on short branches. 



Common in the upper sublittoral zone. Coilodesme Californica often 

 grows on this plant. 



Cystophyllum 

 geminatum 



Postelsia 

 palmaeformis 



PLATE 63 



Fig. 41. a, Branch from upper portion, with small air bladders 

 terminated by receptacles ; b, branch from lower part of plant, showing 

 small blades. X 0.5. 



Fig. 42. a, Cross section of hollow stipe; X 0.33. b, top of plant 

 with group of blades; X 0.2. 



31. POSTELSIA Ruprecht 



1. Postelsia palmaeformis Rupr. Pflanzen aus dem nordl. Th. des Stillen 



Oceans, p. 19, pi. 8. Fig. 42 



Holdfast of thick branching hapteres ; stipe unbranched, stout, hollow, 



about two to four dm. long; blades from sixteen to thirty -two, narrow, 



furrowed, borne on the end of the stipe ; sori in the furrows. 



Growing on rocks along shores exposed to heavy surf. 



32. ALARIA Greville 



Holdfast of stout or slender branching hapteres ; stipe solid, terete 

 or flattened, with or without mucilage ducts ; blade terminal, elongated. 



