HOW TO KNOW THE SEAWEEDS 



137b Tetrasporangial sori restricted to the margins of the blades and 

 (or) to proliferous outgrowths along the margins 138 



138a Blades densely fringed with small, flat or ruffled, overlapping 

 marginal outgrowths to which the tetrasporangia are restricted. 

 Fig. 177 Botryoglossum iarlowianum 



Fig. 177. Botryoglossum tarlowianum 

 (J. Agardh) G. DeToni 



A small terminal portion of a blade 

 showing the system of delicate veins 

 and the development of the dense, 

 marginal fringe of small, overlapping 

 outgrowths, X 1. This is a frequent 

 species on lowest intertidal rocks or 

 below along the entire Pacific Coast 

 except in southernmost California 

 where the plant is found at moderate 

 infratidal depths. It is the only mem- 

 ber of the genus recognized in our 

 area, but, inasmuch as Botryoglossum 

 was founded upon a species from 

 South Africa, there is some question 

 about the true generic identity of the 

 Pacific American plants. Our plant 

 is clearly of very close relationship 

 with Cryptopleura, and separated 

 rather unconvincingly. Fortimately, it 

 can be recognized specifically by the characters of the marginal out- 

 growths mentioned in the key, and also by its large size (to 35 cm. 

 tall) and broad upper blade segments (to 2 cm.). 



Figure 177 



135 



