Prostrate perennial herb; Leaves: Stipules persistent, membranous, lanceolate, 2-4 by 0.9-1.5 mm, base obliquely cordate, apex acuminate, caudate, glabrous. Inflorescence with peduncle 3-4.5(-5.9) cm, bracts absent; Seeds (5-) 10-16 per pod, situated obliquely on the pod, brown, obovoid, compressed, 3.8-4.8 by 2.5-2.7 mm, areole narrow, open towards the hilum.
Asia-Tropical: Cambodia (Cambodia present); Jawa (Jawa present); Lesser Sunda Is. present; Thailand (Thailand present), Flores present, Madura present
Thailand, Cambodia; in Malesia: Java (including Madura), Lesser Sunda Islands (Flores).
Windler (l.c.) used the name Neptunia acimciformis (Span.) Miq. for this species, based on Desmanthus acinaciformis Span.  on material from Timor. I have not been able to trace a Spanoghe specimen nor the 'Icon. no. 60' that is cited in the protologue. Bentham [in ] mentions the name in a note under Neptunia gracilis. I agree, that these two taxa could be conspecific. However, as the description is ambiguous and as both N. dimorphantha and N. gracilis, unlike N. javanica, are found in Timor, the name Neptunia acinaciformis is discarded as dubious.