Aloes and Lilies of Ethiopia and Eritrea

312 DIOSCOREACEAE
Dioscorea gillettii
Description
Habitat and
distribution
widespread to Senegal in the west and to Transvaal
and Angola in the south. The main flowering period in
Ethiopia is from August to September.
This species includes wild varieties with poisonous
tubers and bulbils with alkaloids (dioscorine and dihydrocorti
sone). The wild tubers are eaten in times of famine,
only after repeated washing.
4. Dioscorea gillettii Milne-Redhead
The specific epithet ‘gilletii’ was given in honour of the
English botanist, Jan Gillett, who had collected much
in eastern and ortheastern Africa. One of his collections
from the Kenya­side of Moyale was designated as a type
of the species. The species was described in 1963 by
Milne­Redhead.
It differs from a similar species, D. bul bifera, by the
stems growing only up to 2 m long, male flowers with
3 stamens, and with wingless seeds. In contrast, D.
bul bifera has 3–10 m long stems, male flowers with 6
stamens and winged seeds.
The plant is a small herbaceous twiner, less than 2 m high. Stems
unarmed, glabrous. Tuber perennial, spreading horizontally just
below the soil surface with fringing roots, 3.5–4.5 x2.5–3.2 cm.
Leaves alternate, rarely sub­opposite; petiole 0.5–5 cm long; blade
ovate­cordate, 1.5–9 × 1–7.5 cm, acute to acuminate at the apex,
deeply cordate at the base. Male inflorescences: In the axils of
leaves, 1–14 cm long; with single pedicillate flowers or short 2–4
flower cymules at each node. Male flowers: perianth spreading, 4–5
mm wide; segments elliptic; stamens 3 and staminodes 3. Female
inflorescences: one raceme per leaf axil, usually 2-flowered, rarely
one or more. Female flower: perianth spreading, 5–6 mm wide;
ovary glabrous. Capsule obovate to suborbicular, 2.2–2.7 × 2–3 cm,
winged, with parallel nerves extending from the suture towards the
axis, not reflexed. Seeds without a wing.
The species grows in Acacia-Commiphora-Boswellia
woodland and wooded grassland between 850 and 1650
m in Sidamo and Bale floristic regions. It also occurs in
Kenya. The main flowering period in Ethiopia is from
April to June and also from October to November.