Aloes and Lilies of Ethiopia and Eritrea

318 DIOSCOREACEAE
Dioscorea
sagittifolia
Description
Habitat and
distribution
10. Dioscorea sagittifolia Pax
The specific epithet ‘sagittifolia’ refers to the arrow
shaped (sagitti-) leaf (-folia) bases.
The species was described by Pax in 1892 from a plant
collected in Djur, Central Africa by Schweinfurth.
It differs from the related species D. abyssinica by
having leaves where the the basal lobes are sagittate to
auriculate. In contrast, D. abyssinica has leaves with
the basal lobes being rounded. Of the two varieties, D.
sagittifolia var. lecardii (De Wild.) Nkounkou occurs in
Ethiopia.
Climber, stem 4–5 m long, unarmed, glabrous. Tubers annual,
descending vertically and found deeply (to 40 cm) below the
surface, protected by thorny roots. Leaves opposite, rarely alternate;
petiole 1.5–3.5(–5.5) cm, glabrous; blade firm in texture, ovatelanceolate
to deltoid, 3.7–12 × 1.5–6 cm, tapering, acute at the
apex, often broadly cordate to hastate at the base; 5–7nerved. Male
inflorescences: (1–)2–4 spikes, 1.5–3(–5) cm long, in the axils of
leaves. Male flowers: perianth glabrous, subglobose, 1.5–2 mm;
outer perianth segments with or without a small scarious base.
Female inflorescences: 1–2 spikes, 15–20 cm long, in the axils of
leaves. Female flowers: perianth subglobose c. 2 mm in diameter.
Capsule with waxy cover, 1.9–2.2 × 2.8–3.2 cm. Seeds winged all
round, c. 1.5 × 1.5 cm.
The species grows in open montane forest with Trichilia
dregeana and in woo ded grass land, between 1350
and1700 m in Shewa and Kefa floristic regions. It also
occurs in Uganda, Tanzania, Sudan, and west to Senegal.
The main flowering period in Ethiopia is from April to
July.