Melanospermum rudolfii Hilliard

Annual herb, stem erect to c. 40-120 mm, sparingly branched just above the base, leafy, glandular-puberulous with very occasional longer hairs up to 0.25-0.5 mm long. Leaves opposite, blade c. 6-20 x 3-13 mm, usually elliptic, sometimes ovate, tapering gradually or more abruptly into a flat petiolar part 3-20 mm long, about equalling to half the length of the blade, upper margins coarsely serrate with 2-5 pairs of teeth, both surfaces glandular-puberulous, very occasional hairs on lower margins up to 0.4-0.5 mm long. Flowers up to c. 9 in very lax terminal racemes. Bracts at base of raceme c. 6-16 x 1.5-7 mm, smaller upwards, leaf-like, adnate to pedicel only or to extreme base of calyx as well, glandular-puberulous, very occasional hairs on lower margins up to 0.5 mm long. Pedicels up to 0.8 mm long. Calyx bilabiate, tube c. 1.25-1.5 mm long, anticous lobes c. 2.25-2.5 x 0.75 mm, anticous lip split c. 1.6-1.75 mm, posticous lobes slightly narrower, whole calyx glandular-puberulous, hairs up to 0.3 mm long. Corolla tube c. 4.5 x 0.75 mm broadening slightly in throat, limb c. 5-6 mm across the lateral lobes, posticous lobes c. 1-1.5 x 1-1.25 mm, anticous lobe c. 2-2.5 x 1.25-1.5 mm, all lobes elliptic, white with an orange patch at base of posticous lip and there bearded. Stamens 4, anthers 0.6 mm long, dark violet, all exserted. Stigma exserted. Capsules c. 1.5-2.5 x 1.5 mm Seeds up to c. 20 in each loculus, c. 0.3-0.4 x 0.3-0.4 mm.