prickly spiderflower
Cleome aculeata L.
Prickly spiderflower is a tropical American annual with small flowers and long, narrow seed capsules. In the typical variety described by Flora of North America, the flowering clusters lengthen markedly as the fruits develop. Kew POWO: Cleome aculeataFNA: Hemiscola aculeata var. aculeata
Botanical name
Kew accepts Cleome aculeata L.; Flora of North America treats the same species under Hemiscola aculeata, explicitly citing Cleome aculeata as its earlier name. Kew POWO: Cleome aculeataFNA: Hemiscola aculeata
Recognizing the plant
That typical variety stands roughly thirty to fifty centimetres tall. Leaves divide into three leaflets with finely toothed edges, and short recurved spines occur beside their bases. Glands and glandular hairs occur on the leaves and stalks. White petals contrast with purple stamens. The smooth capsules generally measure about two-and-a-half to four centimetres long and contain ten to twenty wrinkled seeds. Green sepals remain around the developing flower structures. FNA: Hemiscola aculeata var. aculeata
Bloom window
Alabama and Texas, introduced typical variety
For those regional populations of the typical variety, the flora records flowering from late spring through late summer. FNA: Hemiscola aculeata var. aculeata
Native range
Kew gives tropical and subtropical America as the species’ native range. Flora of North America records introduced typical-variety populations in Alabama and Texas. Its regional habitats include roadsides, vacant ground, gravel pits, lakeshores and streambeds, at elevations up to two hundred metres. Kew POWO: Cleome aculeataFNA: Hemiscola aculeata var. aculeata
Botanical sources
Reviewed 2026-10-11. Seasonal development varies with location and growing conditions.