Rotheca louwalbertsii (P.P.J.Herman) P.P.J.Herman & Retief

Perennial herb with annual stems arising from woody rootstock, stems unbranched or sparsely branched near base, 200-500(-800) mm tall, angular, glabrous or pilose. Leaves ternate, sometimes opposite or in whorls of 4, sessile or subsessile, glabrous or pilose, linear to narrowly elliptic, (20-)25-50(-85) x (2-)3-7(-15) mm, decreasing in size upwards, apex acute, base cuneate, margin entire, semi-succulent, glandular-punctate. Inflorescence indeterminate, thyrsoid, bracts similar to leaves but smaller, hypopodium (peduncles) (5-)10-30(-45) mm long, mesopodium 5-16 mm long, epipodium (pedicels) 1.5-4.5 mm long, purplish tinged; prophylls (bracteoles) 2-8(-12) mm long, linear. Flowers zygomorphic. Calyx tubular, 5-toothed, tube 2.5-3.0 mm long, teeth 1-3 mm long, purplish tinged, persistent. Corolla tubular in lower part, with 5 lobes, tube 4-6(-8) mm long, curved; 4 lobes lateral, 5-7 x 3-5 mm, purplish, fifth lobe forming lower lip, 7-10 mm long, darker purple marked with white inverted Y-shaped pattern. Stamens 4, purple, long exserted, opposite lower lip and curved downwards, attached ±1 mm below mouth of corolla tube, bases, where attached to corolla tube, covered with white downwardly directed hairs; filaments 14-21 mm long, anthers 1-2 mm long. Style long exserted, purple, 22-27 mm long, curved, stigma of 2 unequal lobes, upper lobe shortest, ±0.5 mm, lower lobe ± 2 mm long. Ovary 4-lobed in upper part, papillose, 2 mm long, imperfectly 4-locular, with a single ovule in each loculus. Fruit 1-4 drupes, ripe fruit not seen.