Tree. Leaves thinly chartaceous, (obovate-)oblong, 16-26 by 6.5-9 cm, base (long-)attenuate, apex broadly acutish; Inflorescences behind the leaves, with dense or sparse dendroid hairs 0.2-0.3 mm, glabrescent;
Asia-Tropical: Borneo present, Melawi, Bukit Kelawai present, W Kalimantan present
Malesia: Borneo (W Kalimantan: Melawi, Bukit Kelawai, known only from the type).
The male flowers resemble those of the group of species with H. polyspherula (especially var. sumatrana) or//, laticostata, particularly the distinctly triquetrous androecium. However, in the H. polyspherula-group the (sub)erect anthers are mutually free for at least about halfway, whereas in H. pachyrachis the anthers are (almost) completely connate. In general habit and the colour of the leafy twig, H. pachyrachis somewhat resembles the H. polyspherula-group. The connate anthers (and the appearance of the leaves) point to the group of species keyed out around H. fragillima.