A Monograph of the Genus Alarli. '^\ 



Alai'ia ochotensis is the only example in which the petioles of the 

 dropped sporophylls remain permanently attached on the stipe 

 (Plate III, fig. 1). 



In an advanced stage of development, the scars of the dropped 

 sporophylls are often hardly perceptible, except in A. ochotensis. 

 Hence the lower part of the stipe becomes much longer than in 

 the younger stage. Some writers distinguish the sporophy 11- bearing 

 portion of the stipe from the naked, by calling them racliis and 

 and stipe respectively. To a certain extent this distinction appears 

 to hold good in external appearance and in internal structure. 

 But the limitation of the two parts is gradual and unfixed as may 

 be granted from the above elucidation. In the present paper, 

 therefore, both parts are included under the single terra stipe. 



The habitat of the plant undoubtedly influences the length of 

 the stipe of Alaria. In one and the same species, those individuals 

 found in water of less salinity, in a shaded place or in a deeper 

 water have longer and slenderer stipes than those in other condi- 

 tions. It is to be understood that the length of the stipe, in any 

 sense, can not be taken as an important character for specific 

 distinctions. 



JBlade, 



In all species of Alaria the blade is simple for the whole life. 

 But the older parts of fully grown blades are pinnately split, in 

 the mode characteristic to the genus. The general outline of the 

 blade is linear with attenuate, cuneate or roundish base, and a 

 midrib running longitudinally on the median line percurrent from 

 the stipe. The apex of the blade begins to wear away at an 

 early embryonal stage and the process continues as the blade 

 elongates by stipo-frondal growth. 



