6. Studies on the Leaf Structure of Zoysia pungens, 



Willd. 



By M. S. Ramaswami, M.A. (formerly Government Postgraduate 



Research Scholar in Botany, Presidency College, Madras); 

 Officiating Curator of the Herbarium, Royal Botanic Garden, 



Calcutta. 



(With Plates V— VI.) 



The subject of this paper forms really one of a series of 

 investigations on the comparative anatomy of the leaves of 

 South Indian grasses undertaken by me from 1909 onwards, at 

 the suggestion of Prof. P. F. Fyson, to whom I desire to ex- 

 press my thanks for the facilities afforded at the beginning 



of this study. 



Four species of the Natural Order Gramineae are known to 

 me as occurring on the sands opposite the City of Madra 

 within a distance of 150 yards from the sea. They are — 



1. Zoysia pungens, Willd. 



2. Sporobolus virgin icus, Kunth. 



3. Spinifex squarrosus, Linn. 



4. Trachys mucronata, Pers. 



Plants other than grasses noticed in this area were Ipomoea biloba, 

 Forsk, Launea pinnaiifida Cass, and Cyperus arenarius, Retz. 

 These were long known as maritime sand-binding plants on 

 account of the useful purpose they serve by the extensive and 

 interlacing nature of their shoot and root systems in protecting 

 lands from the encroachment of sand blown continually by sea 

 winds. Although the root system of Zoysia pungens is not so 

 extensive as to entitle it to be called a sand-binder, yet, when 

 we consider the smallness of its stem and leaves, we are at once 

 struck by the wonderful extensiveness of the root-stock and its 

 branches. We may, then, safely say that Zoysia pungens, 

 though not an effective sand-binder by itself, forms a valuable 

 aid to the others mentioned above, in accomplishing their 

 purpose. The four grasses enumerated above are not to be 

 regarded as the only ones of their kind found along the sea- 

 shore at Madras, but merely represent those species which are 

 almost always found exclusively growing on maritime sands 

 and which were collected and studied by me. I propose, in 

 this paper, to discuss some of the structural adaptation- 

 noticeable in the leaf of Zoysia pungens, due in great part to 

 the peculiar habitat of the plant. Zoysia pungens, Willd., 

 is a native of the sea-shores of the South-Eastern Asia, 

 Australia and Mauritius. Before beginning to study the pecu- 

 liarities of its leaf-structure, it will be appropriate to give a 



