2 MINNESOTA BOTANICAL STUDIES. 



extends to Port Harford some distance south of San Francisco. 

 Below this point it is replaced by Egregia l&vigata Setchell with 

 its numerous forms. The exact northern limit of distribution is 



not known. 



EXTERNAL MORPHOLOGY. 



The young -plant consists of hold-fast (root area) and frond 

 (shoot area), the latter consisting of a short stipe and a well- 

 developed lamina (Plate II.). The growing point is situated at 

 the base of the lamina. In early life the plant has much the 

 appearance of a young Laminaria or Alarm. The stipe soon 

 branches in the merismatic region, each branch becoming dif- 

 ferentiated into stipe portion (rachis) and lamina. Both rachis 

 and lamina increase in length but the lamina commonly attains 

 a length of only 3 to 5 dm., while the rachis may become very 

 long. Some plants collected in the month of July were 6 to 8 

 meters in length. The lamina grows but very little after the 

 rachis has attained a length of one meter. 



The mature plant may have from ten to forty long branches 

 and be of great size (Plate /.). The branched basal part of 

 the frond resembles the basal part of Lessonia. At the sides 

 of the rachis and lamina of each branch there are rows of 

 closely packed leaf-like proliferations of various shapes. Plants 

 of the related genus Alaria also have phylloid outgrowths but 

 they are entirely confined to the stipe, never appearing on the 

 lamina. 



The holdfast. In large plants this is a convex disc about i 

 dm. in diameter, rather smooth on the attached surface, while 

 the upper surface consists of dichotomously much-branched, 

 overlapping, nearly cylindrical blunt fibers about 5 mm. in 

 diameter, smooth and of a light brown color. 



The stipe. At the point of union with the holdfast the stipe 

 is nearly terete but the first branches are given off within a dis- 

 tance of 2 or 3 cm. and from that point they are all somewhat 

 flattened-cylindrical in shape, becoming at a little distance strap- 

 shaped. This flattened strap shape is maintained the entire 

 length of the rachis of each branch. Branching does not 

 occur at any great distance from the holdfast. The rachis is 

 dark brown in color, distinctly roughened with tuberculate and 

 short ridge-like thickenings. 



The lamina is of a somewhat lighter color than the rachis, 

 is generally 25 to 35 mm. in width and about twelve times as 



