Species as per Flora of India Vol 23 (Editors N. P. Balakrishnan, T. Chakrabarty, M. Sanjappa, P. Lakshminarsimhan & P. Singh- by Botanical Survey of India (2012)):
Dimorphocalyx balakrishnanii Chakrab. & Premanath 221
Dimorphocalyx beddomei (Benth.) Airy Shaw 222
Dimorphocalyx glabellus Thwaites 222
var. glabellus 223
var. lawianus (Hook.f.) Chakrab. & N.P.Balakr. 223
Dimorphocalyx kurnoolensis R.Venkatar. & T.Pullaiah
Genus Dimorphocalyx Thw. (Euphorbiaceae) in India by T Chakrabarty, N P Balakrishnan Proceedings: Plant Sciences October 1990, Volume 100, Issue 5, pp 285-299 –
Abstract : A revision of the genus Dimorphocalyx Thw. (Euphorbiaceae) for India and adjoining countries is presented. Three species and two varieties are recognised. Dimorphocalyx beddomei (Benth.) Airy Shaw is endemic to south India. Dimorphocalyx lawianus Hook. f., endemic to south India is reduced to a variety of Dimorphocalyx glabellus Thw. Dimorphocalyx dilipianus Balakr. and T Chakrab. is reduced to a synonym of Dimorphocalyx balakrishnanii T Chakrab. and Premanath, endemic to Andaman Islands. Keys to the taxa, taxonomic descriptions and illustrations are presented.
The genus Dimorphocalyx Thwaites in now Tritaxis Baill. (Euphorbiaceae) : 2 posts by 2 authors. Attachments (1)- tax.12135- compressed.pdf
Please look at the attached free access publication. There are four species and two varieties of Tritaxis in India.