Impatiens usambarensis Grey-Wilson

Balsaminaceae, C. Grey-Wilson. Flora of Tropical East Africa. 1993

Habit

Rather robust perennial to 2 m. tall, though generally less; stems often reddish, sparingly branched or simple, glabrous or with a few hairs when young, but then soon glabrescent.

Leaves

Leaves spirally arranged; petiole 2.3–6.8 cm. long, slender, with a number of 2–4 mm. long stipitate glands (extra-floral nectaries) crowded at the top; lamina narrowly ovate or oblong to oblong-elliptical, (2.5–)5–18.5 cm. long, (2–)2.5– 5.2 cm. broad, the base attenuate, the apex acute to acuminate, sparsely pubescent above but rather densely so beneath, especially along the midrib and lateral veins; margin serrulate or serrulate-denticulate; lateral veins (8–)9–14 pairs.

Inflorescences

Inflorescence (1–)2(–3)-flowered, the flowers pink to deep red or vermillion.

Peduncles

Peduncle 3–9 cm. long, slender, glabrous or somewhat pubescent.

Bracts

Bracts linear-lanceolate, 4–7 mm. long, acute.

Pedicel

Pedicels 2–3.5 cm. long, slender.

Calyx

Lower sepal narrowly navicular, 15–19 mm. long, abruptly constricted into a 27–41 mm. long curved filiform spur which is slightly thickened at the tip. Lateral sepals 2, narrowly lanceolate, 4–7 mm. long, acute.

Corolla

Dorsal petal suborbicular to obcordate, 22–26 mm. long, 26–30 mm. broad, dorsally with a narrow crest terminating in a short acute point. Lateral united petals (20–)24–30 mm. long; upper petal of each pair suborbicular to obovate, 22–28 mm. long, 14–23 mm. broad, entire or slightly emarginate; lower petal of each pair similar in shape to the upper, 23–28 mm. long, 13–21 mm. broad, entire or slightly emarginate.

Ovary

Ovary glabrous.

Fruits

Fruit fusiform, 17–22 mm. long, glabrous.

Habitat

Rain-forest and forest patches, usually in deep shade, especially along pathways and streams; 850–2100 m.

Distribution

not known elsewhere T3