KELPS 201 
Pacific coasts are the Sea Girdle (Cymathere) with a 
narrow beautifully ribbed “leaf”; the Sea Tree (Lessonia) 
with a stout branching stem bearing many small leaves; 
the Sea Palm (Postelsia) with an unbranched stem bearing 
a tuft of leaves at’the top; the Bladder Kelp (Nereocystis) 
with a long, cord-like stem, often 10 to 15 meters long and 
bearing an air bladder at the top, to which is attached a 
tuft of large leaves; the Giant Kelp (Macrocystis) with a 
long, slender, cord-like stem, sometimes 50 to 75 meters 
long and bearing a row of large leaves toward its extrem- 
ity, each with a basal air bladder; the Leafy Kelp (Egre- 
gia) with a flat stem which bears innumerable lateral leaf- 
lets and air bladders. 
307. The highest of the Brown Seaweeds are the Rock- 
weeds and Gulfweeds (Fucales) in which the plant body is 
of medium size (usually from a decimeter 
to a meter in length), rooted below, and 
massive and branching above. Their 
tissues, too, show a considerable differ- 
entiation; the cells are arranged in cell- 
masses, and these are differentiated into 
several varieties of parenchyma, and other 
tissues approaching, in some instances, to the condition 
which prevails in higher plants. Some species develop 
air bladders in their. tissues. 
308. With the foregoing there is found’a marked differ- 
entiation of portions of the plant body into general re- 
productive organs, analogous to the floral branches of 
higher plants. The sexual organs are developed upon 
modified branches, which differ more or less in shape and 
appearance from those destitute of such organs. 
309. In all Rockweeds the asexual reproduction 
(“propagation’’) has been suppressed, the emphasis being 
placed upon the sexual reproduction (“generation”’). 
Fie. 87.—Fucus. 
