Fucus vesiculosus (BLADDER WRACK) 



A. Classification: 



Division I. Thallophyta. 

 Subdivision I. Algae. 



Class III. Phaeophyceae (brown algae). 

 Order. Fucales. 

 Family. Fucaceae. 

 Genus. Fucus. 



Species, vesiculosus L. 



B. Habitat: 



i. Ascertain the habitat of this plant from your read- 

 ing, class discussion, or field trip, and record it 

 in your laboratory notes at this place. 



C. Naked-eye Characters: 



1. These characters may be best studied by floating a 

 fresh specimen in a dish of sea-water. Material 

 preserved in formalin should be rinsed under the 

 tap, and then floated in fresh water. 



2. Describe the color, shape, and size of the thallus. 

 Does it form lateral branches or approximately 

 equal terminal branches (dichotomy, forking). 



3. Do you find any holdfasts, or organs of fixation? 

 If so, describe them. State reasons why you think 

 they are true roots or not. 



4. Is there a midrib? A stalk, or stipe? Do you 

 consider that the plant is differentiated into root, 

 stem, and leaf? Give reasons. 



5. Describe the distribution of bladders. Why is this 

 species called "vesiculosus?" 



