- A New Variety of Exacum zeylanicum Roxb. 



BY 



T. FETCH, B.A., B.Sc. 



"TN the course of a botanical excursion to Kunadiyapara- 

 -*- witta at Christmas, 1917, Mr. F. Lewis collected a white 

 Exacum, which differed from Exacum Walkeri Arn. in that 

 the flowers were pure white, without the green " eye " which 

 characterizes that species. Further examination of the 

 epecimsn shows that it closely approaches Exacum zeylanicum 

 in most details, and it may, at least provisionally, be regarded 

 as a variety of the latter. 



The leaves are up to 6*5 cm. long, narrow-lanceolate, and 

 usually strongly attenuated towards the tip. In some 

 specimens the leaves, are crowded, the consecutive pairs of 

 leaves being 1 • 5-2 • 5 cm. apart, but in others they are distant, 

 and up to 5 cm, apart. The arrangement of the leaves in the 

 former specimens approaches that of specimens of E. zeylanicum 

 collected by Trimen on Pidurutalagala at 7,400 feet. 



The flowers are few, and the inflorescence lax. The largest 

 available inflorescence bears only eight flowers, and the 

 branches of the inflorescence usually terminate in single 

 flowers. The petals are white, oval, obtuse or subacute, not 

 differing in shape from those of Exacum zeylanicum. 



The only structural difference which separates this form 

 from Exacum zeylanicum is the shape of the anther. In 

 E. zeylanicum the anthers are, normaUy, long and attenuated 

 upwards, frequently attaining a length of 6 mm. ; and they 

 are furnished with terminal pores. In the white form under 

 notice they are comparatively short and stumpy, about 4 mm. 

 long, not noticeably attenuat'^d,' and the apex of the anther 

 is curved towards the inner face, so that the pores are sub- 

 terminal or almost lateral. In their short stumpy form 



Annals of the Royal Botanic Gardens, Peradeniya, Vol. VII.. Part I., July, 1019. 



