HOW TO KNOW THE SEAWEEDS 



46b Branching multifarious 47 



47a Parenchymatous medulla with a central core of relatively slender, 

 longitudinal filaments. Fig. 76 Cystoclonium puTpureum 



Fig. 76. Cystoclonium purpureum (Hudson) Bat- 

 ters 



A small upper portion of a female plant 

 showing the multifarious branching and the 

 presence of swellings in some branches repre- 

 senting cystocarps, X 1.2. Grows attached to 

 shells and rocks at low tide level, New Jersey 

 and northward. Mature plants reach 10-50 cm. 

 in height. 



Figure 76 



47b Medulla parenchymatous in character throughout 48 



48a Older parts of axes with a thin cortex; ultimate branches of vari- 

 able length, indeterminate. Fig. 77 Dictyosiphon (in part) 



Fig. 77. Dictyosiphon foeniculaceus (Hudson) Gre- 

 ville 



A small portion of a plant about 40 cm. high to 

 show the indeterminate character of the branches, 

 X 1.2. This is a widespread and variable species 

 throughout the entire north Atlantic area, having 

 been described from England nearly 200 years ago. 

 It is a common epiphyte on various algae, especially 

 Chordaria, and reaches its best development in sum- 

 mer, although it may be found throughout the year. 

 In our area it is most abundant in New England, 

 but occurs as^far south as New Jersey. Some forms 

 tend to be hollow and may key out best under 

 step 95a. 



Figure 77 



65 



