Dioscorea bulbifera

Linnaeus

Sp. Pl. 2: 1033. 1753.

Common names: Aerial yam potato yam
Introduced
Treatment appears in FNA Volume 26. Treatment on page 484. Mentioned on page 481.

Plants tuberous or not; tubers, when present, buried just below-ground surface, not stalked, globose, weighing less than 1 kg. Stems twining counterclockwise, climbing to more than 20 m, often flecked with purple, unwinged or rarely narrowly winged, terete, producing axillary bulbils frequently greater than 5 cm in diam. in leaf-axils. Leaves alternate throughout, 5–25 × 5–26 cm; petiole usually somewhat shorter than blade, base clasping, basal lobes stipulelike, 1–4 mm wide; blade 5–11-veined, broadly ovate-cordate, glabrous, base orbicular, margins entire, apex long-acuminate. Staminate inflorescences axillary, borne singly, spicate or paniculate, cymose, to 70 cm; cymes reduced to 1 sessile bracteolate flower, internodes ca. 2 mm; secondary axes to 6 per node, fasciculate, subtended by deltate bracteoles or sometimes leafy bracts, 3–20 cm. Pistillate inflorescences borne singly or fasciculate, to 6 per axil, spicate; spikes bearing to 50 flowers, 6–40 cm, subopposite to 8 mm apart. Staminate flowers fragrant; perianth white, becoming purple; tepals in 2 similar whorls, spreading at anthesis, lanceolate, (1–) 2–5 mm; fertile stamens 6 in 2 equal whorls; anthers as long as or longer than filaments; thecae distinct, not spreading. Pistillate flowers: perianth greenish white, not changing color; tepals as in staminate flowers; staminodes 6, smaller than fertile stamens. Capsules not reflexed at maturity, longer than wide, 1.8–2.8 × 1–1.5 cm. Seeds unilaterally winged, 12–20 mm. 2n = 80, 100.


Phenology: Flowering late summer–early fall.
Habitat: Near ponds, marshes, drainage canals, disturbed woods and thickets, waste areas
Elevation: 0 m

Distribution

V26 1006-distribution-map.jpg

Introduced; Fla., tropical Asia, tropical Africa

Discussion

Dioscorea bulbifera is the most widely distributed of all Dioscorea species. It is found throughout the tropics and is thought to be native to both Africa and Asia. The tubers are either small and bitter or do not form at all. The bulbils are eaten, although this species is not widely consumed outside of Oceania. It is weedy in Florida and probably elsewhere in the Gulf States, but I have not seen any specimens to document its range outside Florida. Plants in the flora area rarely flower, and those that do are usually pistillate; I observed no staminate flowers.

Selected References

None.

Lower Taxa

None.
... more about "Dioscorea bulbifera"
tetrasporangiate +
Lauren Raz +
Linnaeus +
stipule-like +
orbicular +
ovate-cordate +
1.8 cm18 mm <br />0.018 m <br /> (2.8 cm28 mm <br />0.028 m <br />) +
longer than wide +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Aerial yam +  and potato yam +
long-appendiculate +
bracteolate +
reduced +
Fla. +, tropical Asia +  and tropical Africa +
pistillate +, staminate +, bracteolate +  and sessile +
fragrant +
50 +  and 1 +
3-winged +  and capsular +
loculicidal +
perennating +
Near ponds, marshes, drainage canals, disturbed woods and thickets, waste areas +
grouped +  and paniculate +
spicate +, pistillate +, cymose +  and staminate +
paniculate +  and singly +
0 cm0 mm <br />0 m <br /> (70 cm700 mm <br />0.7 m <br />) +
cymose +, spicate +, unbranched +  and branched +
racemose +  and paniculate +
2 cm20 mm <br />0.02 m <br /> (?) +
0 +  and 1 +
5cm;25cm +
5 cm50 mm <br />0.05 m <br /> (26 cm260 mm <br />0.26 m <br />) +
2-3 times length of perianth +
parietal +, axile +  and placentation +
campanulate +  and rotate +
usually somewhat shorter +
Flowering late summer–early fall. +
3 cm30 mm <br />0.03 m <br /> (20 cm200 mm <br />0.2 m <br />) +
compressed +
W1 +  and Introduced +
apart +  and subopposite +
0 cm0 mm <br />0 m <br /> (?) +  and 0.8 cm8 mm <br />0.008 m <br /> (?) +
winged +  and unwinged +
flecked with purple +
persisting +, or +  and renewed +
climbing +  and twining +
than for more a single growing season +
persistent +
distinct +
below-ground +  and buried +
Dioscorea bulbifera +
Dioscorea +
species +
0.3 cm3 mm <br />0.003 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
distinct +
not spreading +
divided +
not +  and tuberous +
expanded +