HOW TO KNOW THE SEAWEEDS 

 134b Blades without such rows of cryptostomata 135 



135a Holdfast stupose (felted, fibrous). Fig. 173 Diciyopteris 



Fig. 173. Diciyopteris polypodioi- 

 des (Desfontaine) Lamouroux 



Two young blades shown aris- 

 ing from the spongy, felted (stu- 

 pose) holdfast. X 0.75. This spe- 

 cies is occasional along the At- 

 lantic Coast from North CaroHna 

 southward. In Florida three other 

 species may be encountered of 

 which D. justii is the most spec- 

 tacular, being up to 40 cm. high 

 and with blades from IV2 to 4 

 cm. broad. The other two species, 

 D. delicatula and D. plagiogram- 

 ma, are smaller and distinguished 

 by the irregular, tangled, dicho- 

 tomous branching of the former 

 and the irregular, alternate branch- 

 ing of the latter with small lateral 

 veins leading out toward the mar- 

 gins. 



In southern CaUfornia another 

 species, D. zonarioides, is a com- 

 mon inhabitant of rocky tide pools, 

 especially those which are some- 

 what shehered and well insolated at low tide. In such habitats it may 

 be a luxuriant and dominant member of the vegetation which cannot 

 help but attract attention when sunUght brings out the irridescent 

 highlights of its fronds. 



Figure 173 



132 



