14. Note on Leaf Variation in Heptapleurum v*nutosum 3 



Seem* 



By M. S. Ramaswami, MA. (Cal.), B.A. (Mad), 



Officiating Curator of the Herbarium, Royal Botanic Garden, 



Calcutta. 



[With Plates XII— XIV.] 



The late Mr. C. B. Clarke in his account of the Natural 

 Order Araliaceae in the Flora of British India when dealing with 

 the genus Heptapleurum has put H. venulosum Seem, under a 

 section of the subgenus Euheptapleurum which includes plants 

 whose leaves are simply digitate and leaflets are 5 to 7 in num- 

 ber as distinct from another section of the same subgenus which 

 consists of those having twice digitate or digitately decompound 

 leaves. 



Observations made on shrubs of this species growing in 

 the Royal Botanic Garden, Sibpur, tend to prove that this 

 distinction, at any rate as far as this species is concerned, cannot 

 always be relied upon. The leaves of Heptapleurum venulosum 

 Seem, vary very widely along several lines to such an extent 

 that on the same shrub we find all sorts of intermediate forms 

 between a compound leaf having two leaflets and a twice 

 digitate leaf containing 24 leaflets (i.e. 8 ternate leaflets). The 

 chief lines of variation, however, are: 



(1) Frequent changes in the shape and size of individual 



leaflets. 



(2) Increase in the number of leaflets (from 2 to 24). 



(3) A gradual transformation from a simply digitate to a 



twice digitate arrangement. 



The accompanying three plates were drawn from specimens 

 collected on two shrubs and show the more interesting varia- 

 tions. As nothing has been published regarding this wide 

 range of leaf- variability in this species and as it is desirable that 

 this should be on record for the use of Systematic Botanists 

 generally, I venture to present this small note for the considera- 

 tion of the members of the Society. 



EXPLANATION OF PLATES. 



Plate XII. -The figures show the variation in shape, size and 



number of leaflets. 



Plates XIII and XIV.— The various intermediate forms found 



between a compound leaf (consisting of two large 

 leaflets and a small one) and a twice digitate leaf 

 (consisting of 24 leaflets, i.e. 8 ternate leaflets). 



