Aloes and Lilies of Ethiopia and Eritrea

316 DIOSCOREACEAE
Description
Habitat and
distribution
Dioscorea abyssinica
Description
Wendawek Abebe (2008), that carried out molecular
research in the species complex in the south and SW
Ethiopia considered the two cultivated species (Dioscorea
cayensesis and D. rotundata that form a complex) to be
the same as the wild D. praehensislis and kept them
under the oldest name D. cayenensis, a concept followed
here. The complex differs from the related species, D.
abyssinica and D. sagit tifolia by usually having spines on
the stem and a petiole that is not widening at the base.
Annual twiner.Stems prickly or unarmed. Superficial roots prickly
or unarmed. Leaves opposite above, alternate at the base, sometimes
the basal leaves modified and reduced to cataphylls; petiole 5–12
cm long; blade broadly ovate to sub orbicular, 6–12 × 5–10 cm,
acuminate at the apex, broadly cordate at the base; 5–7nerved.
Male inflorescences: 1–3 spikes, 4–6 cm long in the axils of leaves.
Female inflorescences: 1–2 spikes in the axils of leaves, 10–12 cm
long, few-flowered. Capsule 2–2.5 × 3–3.5 cm. Seeds winged all
round, 1–1.5 × 1–1.5 cm.
The species is cultivated between 1700 and 1800 m in
Kefa and Sidamo floristic regions and grows wild in
secondary forests between 550 and 1600 m in Sidamo,
Kefa, Illubabor floristic regions. It is also cultivated
and widespread throughout tropical Africa. The main
flowering period in Ethiopia is from April to June and
from September to October. The tubers of the wild forms
are eaten during famine.
9. Dioscorea abyssinica Hochstetter ex Kunth
The specific epithet ‘abyssinica’ refers to the former name
of Ethiopia, Abyssinia. The species name was proposed
by Hoch stetter, and the species was described by Kunth
in 1850 from a plant collected in Djeladjeranne, Tigray
floristic region by Schimper.
It differs from the related species D. sagittifolia
by having leaves where the basal lobes are rounded.
In contrast, D. sa git tifolia has leaves with sagittate to
auriculate basal lobes.
Climber, stems growing 2–5 m long, unarmed, glabrous. Tubers
annual, edible, growing deep in the ground, up to 6 × 2–3 cm,
cylindrical, slender, sometimes branched; flesh generally white or
light lilac. Roots unarmed. Leaves generally opposite; petiole 3–6
cm long, glabrous; blade cordate­ovate, broadly elliptic to triangular,
4–12 × 2–6 cm, acuminate, cuspidate at the apex, cordate at the