Streptocarpus saxorum Engl.

Gesneriaceae, Ian Darbyshire. Flora of Tropical East Africa. 2006

Type

Type: Tanzania, Lushoto District, Usambara Mts, Lutindi, Holst 3388 (B†, holo.; K!, iso.)

Morphology General Habit

Succulent perennial herb

Morphology Stem

Basal stems straggling, woody, longitudinally wrinkled in dry material; flowering stems erect, densely pubescent or pilose; leaf scars prominent on bare lower stems

Morphology Leaves

Leaves opposite, crowded in the upper section of the stems, pairs equal; blade fleshy, ovate-elliptic, 1.2–3(–3.8) cm long, 0.7–1.2(–2) cm wide, base obtuse to rounded, shortly attenuate in largest leaves, margin revolute, entire, apex obtuse, surfaces pubescent, densely so beneath particularly along the raised lateral nerves, some hairs glandular; lateral nerves 5(–6) pairs, ascending; petiole 0.2–1 cm long, pilose

Morphology Reproductive morphology Inflorescences

Inflorescences axillary, solitary, 1–2-flowered; peduncles redtinged, 7.5–13.5(–17) cm long, glabrate except for sparse glandular hairs towards base, peduncles of old inflorescences sometimes persisting at lower axils; pedicels 7–15 mm long, glabrous; bracts minute, pubescent

Morphology Reproductive morphology Flowers Calyx

Calyx lobes oblong-lanceolate, 2–3.5 mm long, pubescent outside, with stalked glands within

Morphology Reproductive morphology Flowers Corolla

Corolla white except for lobes pale- to mid-violet, (23–)27–40 mm long; tube 13–20 mm long, glandularpilose outside, sparsely pilose to glabrous inside, saccate at the base, where ± 4.5 mm deep, narrowing to 2.5–4 mm before abruptly deepening to 4.5–6 mm midway along the tube, mouth open but laterally compressed; limb bilabiate, highly oblique; upper lip reflexed, two lobes rounded, 5–10 mm long, 5.5–9.5 mm wide; lower lip protruding, (10–)13.5–23 mm long, lateral lobes 6–12 mm long, 6–13.5 mm wide, rounded, median lobe (6–)8–14 mm long, (6–)8–16 mm wide, sometimes slightly emarginate, shortly ciliate, palate sparsely pilose at the mouth

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens arising from immediately above the deepening of the corolla tube.

Morphology Reproductive morphology Flowers Androecium Stamens Filaments

Filaments 1.7–2 mm long, pubescent with or without glandular hairs.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers subtriangular, 1.7–2 mm wide, thecae indistinct.

Morphology Reproductive morphology Flowers Androecium Staminodes

Staminodes 1–2 mm long

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary narrowly conical, 6–8 mm long, densely appressed-pubescent and with stalked glands.

Morphology Reproductive morphology Flowers Gynoecium Style

Style to 1 mm long, thick, down-curved.

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigma flattened, shallowly bilobed, glutinous

Morphology Reproductive morphology Fruits

Capsule 28–50 mm long, (2–)2.5–4.5 mm diameter, appressed-pubescent, style persistent

Morphology Reproductive morphology Seeds

Seeds ± 0.45 mm long, longitudinally ridged with scalariform transverse ridges.

Ecology

On rocks and cliff faces, usually exposed to full sunlight, often in areas which receive periodic mist-derived moisture, occasionally near rivers; 500–2000 m

Conservation

Although somewhat localised in distribution, this species is recorded as locally common by several collectors within suitable habitat, where it may dominate the vegetation. Due to the inaccessibility and low agricultural potential of its rock and cliff habitats, there appears to be little anthropogenic threat. It is thus assessed as of Least Concern (LC)

Distribution

Flora districts: K7 T3 T6 T7 Range: Not known elsewhere

Use

Cultivated as an ornamental