Ruellia richardsiae Vollesen

Acanthaceae (part 2), Kaj Vollesen. Flora of Tropical East Africa. 2008

Type

Type: Tanzania, Iringa District: Ruaha National Park, Mbage Camp, Richards 20950 (K!, holo.; EA!, K!, iso.)

Habit

Erect shrubby perennial herb to 60 cm tall with several stems from woody rootstock; young stems with sparse to dense spreading thin pilose hairs to 4 mm long and sparse to dense stalked capitate glands to 2 mm long

Leaves

Leaves with petiole 2.5–3.8 cm long; lamina ovate to cordiform, largest 6–9 × 4.5–6 cm, apex acute or narrowing into a weakly defined tip, base truncate to subcordate, sparsely pubescent, densest along veins

Flowers

Flowers solitary, axillary; pedicels 7–17 mm long; bracteoles foliaceous, 2–3 × 1–2.3 cm; petiole 5–10 mm long

Calyx

Calyx 32–38 mm long, divided to 2–3 mm from base, pilose with white glossy hairs and usually also with dense stalked capitate glands; lobes linear, 2–3.5 mm wide

Corolla

Corolla opening in the evening, fallen by early morning, pure white; tube 14–15 cm long of which the basal cylindric part 12.5–13.5 cm and the throat 1.5–2.5 cm long; lobes 2–2.5 × 2–2.8 cm, broadly ovate to reniform with broadly rounded apex

Stamens

Stamens exserted, slightly didynamous; filaments fused for ± 4 mm at base, free parts ± 10 and 11 mm long, all four hairy throughout; anthers ± 8 mm long

Ovary

Ovary not seen.

Stigma

Ventral stigma lobe ± 2 mm long, dorsal ± 0.5 mm long

Fruits

Capsule and seed not seen.

Ecology

Acacia-Commiphora-Combretum woodland and wooded grassland; 800–900 m

Note

I have only seen these three collections but Björnstad (l.c.) cites additional collections. Differs from R. bignoniiflora – which occurs both to the north and south – in the much larger flower parts. It might eventually be treated as a subspecies.

Distribution

Range: Not known elsewhere Flora districts: T7