Dioscorea bulbifera L.

Distribution

Biogeografic region: Andean, Guiana Shield. Elevation range: 34–1630 m a.s.l. Cultivated in Colombia. Naturalised in Colombia. Colombian departments: Antioquia, Bolívar, Cauca, Córdoba, Vaupés.

Habit

Climbing.

Ecology

Habitat according IUCN Habitats Classification: forest and woodland, savanna, shrubland.

Vernacular

Ñame volador

Dioscoreaceae, E. Milne-Redhead. Flora of Tropical East Africa. 1975

Morphology General Habit

Tuber perennial, usually irregularly subglobose, but occasionally elongate, and sometimes absent.

Morphology General Indumentum

Plant glabrous or the leaf-blade inconspicuously puberulous at the base beneath.

Morphology Stem

Twining stems up to 12 m. long.

Morphology Leaves

Leaves as in 3, D. asteriscus.

Vegetative Multiplication Tubers

Aerial tubers irregularly subglobose or markedly angular, up to 7 cm. in diameter, brown.

Morphology Reproductive morphology Inflorescences

Inflorescences as in D. asteriscus, except that the ♂ flowers are sessile and directed downwards, towards apex of inflorescence.

Morphology Reproductive morphology Flowers

Perianth lobes of ♂ flower not spreading; tepals lanceolate, up to 2 mm. long. Perianth lobes of ♀ flower directed towards apex of inflorescence, up to 2 mm. long.

sex Male

Perianth lobes of ♂ flower not spreading; tepals lanceolate, up to 2 mm. long.

sex Female

Perianth lobes of ♀ flower directed towards apex of inflorescence, up to 2 mm. long.

Morphology Reproductive morphology Fruits

Capsule and seeds similar to those of D. asteriscus, but capsule only 2 cm. long and 1.2 cm. in diameter.

Bernal, R., G. Galeano, A. Rodríguez, H. Sarmiento y M. Gutiérrez. 2017. Nombres Comunes de las Plantas de Colombia. http://www.biovirtual.unal.edu.co/nombrescomunes/

Vernacular

ñame papa, ñame volador, papa de aire

Dioscoreaceae, J. Miège. Flora of West Tropical Africa 3:1. 1968

Morphology General Habit

Glabrous non-spiny climber 10-20 ft. high

Vegetative Multiplication Bulbils

Bulbils 1-8 cm. in size, toxic or edible according to the variety

Vegetative Multiplication Tubers

Tubers renewed annually, globose, absent in several varieties or according to the method of cultivation

Morphology Reproductive morphology Flowers

Female flowers, when produced, white turning pink and then purple when old.

sex Female

Female flowers, when produced, white turning pink and then purple when old.

Note

Some edible cultivated varieties with large leaves have lost their ability to produce flowers, the bulbils are then larger and composed of a larger number (4-5) of buds. Wild varieties with toxic, angular, greyish bulbils and medium-sized leaves occur and others with small purplish bulbils, small leaves with a red base to the petiole.

J. R. Timberlake, E. S. Martins (2009). Flora Zambesiaca, Vol 12 (part 2). Royal Botanic Gardens, Kew

Type

Type Plate facing p.217 in Hermann, Paradisus Batavus (1698).

Morphology General Habit

Climber, stem annual to 5 m

Vegetative Multiplication Tubers

Tuber perennial, irregularly ovoid to subglobose, sometimes absent

Vegetative Multiplication Bulbils

Bulbils 0.6–3 cm wide, subglobose to ovoid in non-cultivated forms, flattened, angular to 10 cm long in cultivated forms, grey-brown to purplish-brown, warty

sex Male

Male inflorescence simple or compound, flowers sessile, turned toward inflorescence apex in both genders; male flower tepals (sub)erect at anthesis, pale green in bud, pale pink on opening and at anthesis, maroon-purple post-anthesis, outer tepals 1.7–2.3 0.4–0.8 mm, lanceolate to narrowly elliptic, narrowly oblong or rarely lorate, inner tepals 1.4–2.2 0.3–0.6 mm, narrowly oblong to narrowly oblong-elliptic or more narrow; female flowers with erect tepals

Morphology Reproductive morphology Fruits

Capsule as D. steriscus but 1.5–2.2(3 × 0.95–1.5 cm, oblong to oblong-elliptic in outline, apex not triangularly acute but rounded to subtruncate; seed basally winged.

Distribution

Caprivi, Zambia, Mozambique. Widespread in tropical Africa and Asia, the only species found on both continents.

Ecology

In various forest and woodland types, including mopane. It may require higher rainfall and nutrient levels than D. asteriscus; 200–1300 m. Flowering in February and March; fruiting from March onwards.

Conservation

Conservation notes Widespread species; not threatened. Possibly introduced.

Vernacular

It is known as air or aerial yam, air potato or bulbil yam in English, but has many vernacular names.

Note

The frequency of cultivation of D. bulbifera gives rise to doubts as to whether it is native to both continents. No male material of D. bulbifera has been collected in the Flora area, perhaps because female races are preferred in cultivation. This raises the intriguing question of how female plants in southern Africa set fruit and supports the assertion that it may not be native.

Bernal, R., Gradstein, S.R. & Celis, M. (eds.). 2015. Catálogo de plantas y líquenes de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá. http://catalogoplantasdecolombia.unal.edu.co

Distribution

Cultivada en Colombia; Alt. 34 - 1630 m.; Andes, Guayana y Serranía de La Macarena, Valle del Cauca, Valle del Magdalena.

Morphology General Habit

Trepadora

Use

Dioscorea bulbifera has been domesticated in Africa and a number of edible races exist that have larger and more palatable bulbils and are eaten after boiling (see Burkill in Bull. Jard. Bot. État 15 357, 1939 and Chevalier in Bull. Mus. Natl. Hist. Nat., sér.2, 8 524, 1936). As well as being used as a starchy food source, certain races are also used medicinally, socially or as poisons.