Habenaria tweedieae Summerh.

Orchidaceae, V. S. Summerhayes. Flora of Tropical East Africa. 1968

Morphology General Habit

A terrestrial herb 4 dm. to 1 m. high.

Vegetative Multiplication Tubers

Tubers elongate-ovoid, ± 4 cm. long and 1 cm. in diameter, ± tomentose.

Morphology Stem

Stem erect, rather stout to stout, leafy throughout its length.

Morphology Leaves

Leaves 9–15, the lowermost often reduced to a sheath, the 2–5 middle ones ± spreading, lanceolate, elliptical-lanceolate or oblong-elliptical, acute, the largest 8–25 cm. long and 2–5 cm. broad, the upper ones smaller, ± adpressed to the stem, lanceolate, acuminate, similar to the lower bracts.

Morphology Reproductive morphology Inflorescences

Inflorescence 10–45 cm. long, 4.5–6.5 cm. in diameter, rather closely 15- to many-flowered; rhachis with scattered hairs.

Morphology Reproductive morphology Inflorescences Bracts

Bracts rather thin and chaffy, lanceolate, acuminate, 1.5–3.8 cm. long, the lower ones equalling the pedicel with ovary, sparsely hairy, often with denticulate margins.

Morphology Reproductive morphology Flowers

Flowers half-erect or curved outwards, green with whitish centre; pedicel with ovary nearly straight, 2.5–3.5 cm. long, the ovary sometimes sparsely hairy.

Morphology Reproductive morphology Flowers Calyx

Dorsal sepal erect, convex, narrowly elliptical, obtuse, 6–7 mm. long, 2.5–4 mm. broad; laterals deflexed, obliquely semi-orbicular, acute, 8–10 mm. long, 4.5–6.5 mm. broad; all sepals with short scattered hairs on the outer surface.

Morphology Reproductive morphology Flowers Corolla

Petals bipartite nearly to the base; posterior (upper) lobe erect or incurved, often ± adherent to the dorsal sepal, linear or oblanceolate-linear, acute, 6–7.5 mm. long, 1–2 mm. broad, ciliolate and puberulous; anterior lobe spreading forwards, curved-lanceolate, acute, 9—11 mm. long, 1.5–3 mm. broad, puberulous especially towards the base.

Morphology Reproductive morphology Flowers Labellum

Lip deflexed, tripartite nearly to the base; middle lobe incurved towards the apex, linear, 10.5–12.5 mm. long, ± 1 mm. broad; side lobes linear, 5- 8.5 mm. long, ± 0.5 mm. broad.

Morphology Reproductive morphology Flowers Spur

Spur parallel to the ovary or somewhat incurved, swollen in the apical half, ± 2.5 cm. long.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anther ± 3 mm. high, loculi reclinate, canals slightly upcurved, nearly 3 mm. long.

Morphology Reproductive morphology Flowers Gynoecium Stigma

Stigmas porrect, rather stout, apices swollen and truncate, 2.5–5 mm. long.

Morphology Reproductive morphology Flowers Rostellum

Rostellum linear, subacute or obtuse, 2–3 mm. high, projecting above the anther-loculi.

Figures

Fig. 18, p. 104.

Habitat

In grass on rocky hills, often among scrub; 1950–2350 rn.

Distribution

K3 K4 K5 U2 U3 not known elsewhere