It is an annual plant that grows from 5 to 20 cm tall.

Obovate or elliptical leaves, about 5-30 per plant, are scattered along the elongate, glabrous stem.

Inflorescences are 5–8 cm long and produce pink or red flowers.

S. inconspicuum is endemic to Java and is one of the few Stylidium species that are not native to Australia.

Its habitat is recorded as being moist areas in grass-dominated fields at an altitude of 20–30 metres.