Acanthopsis horrida Nees

Perenial shrublet, 20-50 cm tall. Stems brown (rarely maroon), ribbed, hirsute with deflexed to spreading short, white hairs; internodes (8-)10-15(-20) mm long. Leaves lanceolate to linear, 35-45(-60) x 8-10(-11) mm, indumentum variable, usually almost glabrous to strigose with appressed short hairs interspersed with subsessile glandular hairs; margin undulate, very coarsely dentate-spinose, spines rigid, 4-7 mm long, yellow; base attenuate, decurrent. Inflorescences globose to cylindrical or conical, sessile to subsessile with short peduncle (nearly always <5 mm long); (25-)40-60 mm long, 9-12(-15) mm in diameter. Bracts ovate, obovate to wedge-shaped, 14-20(-26) mm long, base 4-8(-14) mm long; middle to upper bracts ending in 5(-7) primary spines; central primary spine usually compound with 2(or 3) pairs of marginal secondary spines, lateral spines with 1 (or 2) basal secondary spines and 1-3(-5) marginal secondary spines; lateral primary spines slightly longer than central primary spine or same length; spines spreading, rarely recurved in fruit; bract base usually hirsute to pubescent with deflexed to spreading short hairs, often villose with long, silky hairs; spines almost glabrous to pubescent, with some subsessile glandular hairs in centre, usually with long, silky hairs on margin. Bracteoles lanceolate to linear, 7-9 mm long, silky hairy. Calyx tips tinged brown or maroon; dorsal sepal ovate, cuspidate, 10-14 mm long, silky hairy especially adaxially, often with short, spreading hairs abaxially, 7-9-veined from base; ventral sepal ovate, 10-11 mm long, silky hairy especially adaxially, often with short, spreading hairs abaxially, 5-7-veined from base; lateral sepals lanceolate, 7-8 mm long, silky hairy especially at base and along margins. Flowers blue to blue-purple with white throat; corolla 23-29(-33) x 11-15(-18) mm, tube 8-10 mm long, pubescent; central lobe usually as long as wide, constricted at base, truncate to emarginate. Stamens with purple-black anthers, 2(-3) mm long; filaments 4-5(-7) mm long, glandular. Style with patch of glandular hairs at base. Capsules ovate, flattened, glabrous, shiny, 8 x 4 mm, 2-seeded. Seeds 5 x 4 mm, covered with long white hygroscopic hairs.