Some Physiological Observations on 

 Nelumbo nucifera, Gsertn. 



By 



K. Miyake. 



( With PL IV.) 



Nelumbo nucifera, Gsertn. (= Nelumbium speciosum, W.) is a well 

 known " Water-lily " in Asia. Though this plant is not indigenous to 

 Japan, it is planted and flourishes everywhere in the warmer part of the 

 country. Being thought to be sacred, it is always found in the ponds of 

 Buddhist temples. It is also cultivated on farms for the sake of rhizome, 

 which is edible. In our climate the leaves die off late in autumn, while 

 the rhizome remains buried deep in the mud under water during winter. 

 With the spring there come up from the rhizome the new shoots, each of 

 which grows to a large leaf with a long stalk, thus often covering the 

 whole extent of the pond. The flower-bud, borne on the apex of a long 

 stalk, which is exactly alike that of the leaf, sprouts out in the summer. 



As Nelumbo is somewhat isolated among the Nymphceacece it is 

 worthy of careful examination by the botanist. An elaborate morphological 

 study of it was indeed made by Wigand and Dennert 1} some ten years 

 ago, but its physiological investigation is yet untouched. The great size of 

 its vegetative and reproductive organs and their rapid vigorous growth 

 evidently fit it for such an investigation. The following observations were 

 made on the plants growing in the pond of the Botanical Garden of the 

 Imperial University in Tokyo, as extra-study, while I was engaged on 

 other work this summer. I am very sensible of the incompleteness of 

 my observations, and only present this account of them as a preliminary 

 contribution to the physiology of Nelumbo nucifera. In the following 

 pages are given observations on the rate and mode of growth of the leaf 

 and flower stalks, along with others upon the flowering and upon assimila- 

 tion and transpiration. 



1) Wigand-Dennert : Nelumbium speciosum W. Eine monographische Studie. 

 BibliothecaJBotaiiica, Heft No. 11, 1888. 



