Bonnaya aculeata is very closely with B. ciliata but it is diferrent by having pinnatifid bract, the anterior 2 lobes of the calyx are pinnatifid and often capitate inflorescences presenting.
Least concern (LC)
Small annual herbs, 4–30 cm tall; stems erect, quadrangular, glabrous. Leaves obscure pinnately nerved; sessile; lamina linear to linear oblong, 1–5 x 0.1–0.5 cm, apex acute to acuminate, base cuneate, marginss aristate-serrate, glabrous, somewhat sparsely pilose. Inflorescences terminal and axillary raceme or capitate; pedicel 3–4 mm long, not deflexed when fruiting; bracts leaf-like, lanceolate, ovate, somewhat irregularly pinatilobed, 3–10 mm long. Calyx 3–6 mm long, 5-lobed; lobes narrowly lanceolate, apex acute, margins entire or pinnatifid, glabrescent. Corolla white, pink or lilac, 7–10 mm long; glandular hairs along corolla tube, upper lip oblong, apex slightly emarginsate, marginss entire, 1–1.5 mm wide; lower lip broadly 3-rounded lobes, apex obtuse, marginss entire, 4–6 mm wide. Stamens 2 fertile, 2 staminodes; filaments glabrous, posterior straight, ca. 1.2 mm long, anterior filliform, broadly applanate along to the base, apex hooked-like, ca. 1 mm long. Capsules cylindrical, glabrous, 4–10 x 0.5–0.6 mm, longer than calyx lobes. Seeds numerous, dark brown, dark greyish brown or black, ovoid, obovoid, ellipsoid or narrowly ovoid with longitudinal pit canal, plano-convex at top view, 0.3‒0.8 x 0.28‒0.5 mm, pitted.
Laos and Cambodia
Open areas, sandstone ground, in edge of paddy field and dry diptercarp forest; 100‒500 m altitudess; flowering and fruiting August‒January.