1917 



Muenscher; Key to Phaeophyceae 



263 



Costaria costata 



Laminaria Andersonii 

 PLATE 53 



Fig. 

 Fig. 



15. Sketch of plant. X 0.1 to 0.05. 



16. Diagrammatic sketch of plant. X about 0. 1. 



KEY TO SPECIES 



A. Mucilage ducts lacking in the stipe, present in the blade. 



B. Stipe cylindrical; blade simple, thin, light brown. 1. L. saccharina 

 BB. Stipe flattened above ; blade usually split, thick, dark brown. 



2, L. complanata 

 AA. Mucilage ducts present in both stipe and blade. 



C. Stipe long, cylindrical, or compressed only toward the apex ; blade 



split, smooth, without 2 rows of folds. 3. L. Andersonii 



CC. Stipe short, flattened from shortly above the base; blade entire or 



split, usually with 2 rows of folds. 4. L. hullata 



1. Laminaria saccharina (L.) Lamour. Essai. p. 22. Fig. 17 



Holdfast composed of branched hapteres forming a cone-shaped mass ; 



stipe terete, solid, one to six cm. long, spreading above into the broad 



blade ; blade more or less flat or folded, undulate, about one to two meteres 



long, two to six dm. wide, thin and light brown in color ; mucilage ducts 



present in blade only. 



The species is common in the upper sublittoral zone. The two forms 



Li. saccharina f. linearis and L. saccharina f. membranacea also occur in 



this region. 



