320 



Ptib. Puget Sound Biol. Sta. 



Vol. 2, No. 53 



In a series of 58 mature specimens the variation in length of main 

 axis is from 23 cm. to 8 m., and, in width from 4 to 40.5 cm. Increase in 

 length seems to have no relation to increase in width. These mature 

 plants bear from 3 to 24 pairs of lateral branches, the number of pairs 

 seemingly having no relation to the length or width of the main axis. The 

 lateral branches vary in length from 21 cm. to 2.5 m., and in width from 

 3.5 to 23 cm. Table 1 gives some idea of the variation among mature 

 plants. It is evident that it would be exceedingly difficult to find a point 

 where a division could be made on the basis of width of frond. 



The specimens of Desmarestia ligulata (Lightf.) Lam. var herbacea. 

 (Turn.) J. Ag., distributed by Tilden (1898), belong here. She includes 

 part of a young plant of the narrow form, and also one of medium width. 



Table 1. Desmarestia latissima, mature, with holdfasts, tabulated 

 according to length of main axis. 



