RED ALGAl. 201 



Q,Qx\\i^.— RHABDONIA* Harv. 



RhABDONIA TENERA,t AG. 



This genus is represented by one species on each 

 of our American coasts. The one named first is the 

 Atlantic plant. It is found only south of Cape Cod, 

 where it is a very common but somewhat variable 

 plant. In general appearance it is not greatly unlike 

 Gracilaria multipartita, differing mainly in color, 

 and in having a cylindrical and not a flattened frond. 

 The stem and branches are somewhat stouter than 

 a wrapping twine. 



The plant grows from six to twelve inches high, 

 is very irregularly branched, the branches longest near 

 the bottom of the frond, shorter toward the top, but 

 always attenuated at base and apex. Sometimes the 

 main stem runs through the whole plant, sometimes 

 it is so divided into large branches as to be quite lost 

 sight of. The branches themselves also divide, in a 

 manner between branching and forking, and even the 

 somewhat profuse secondary branches not infrequently 

 have scattered ramuli upon them. 



The frond manifests a marked tendency to flatten- 



* Rhabdonia = Rod-like, 

 t Tenera = Tender. 



