Dioscorea transversa
common yam vine
Overview
Dioscorea transversa is a perennial twining vine growing from a deep underground tuber, with annual stems that climb 10-20 feet (3-6 m) into surrounding vegetation each season. The stems twine and bear heart-shaped to arrow-shaped leaves 1.5-4 inches (4-10 cm) long with prominent curved veins, arranged alternately along the stem. Small greenish-yellow flowers about 0.1 inch (2-3 mm) across hang in slender spikes from the leaf axils in summer; male and female flowers occur on separate plants. Female plants produce papery three-winged capsules 0.6-1 inch (1.5-2.5 cm) long that release flat winged seeds. The edible tuber is cylindrical, 8-24 inches (20-60 cm) long, growing straight down, and was a traditional food of Aboriginal people. Top growth dies back in winter and regrows from the tuber in spring. The vine climbs by twining only, with no tendrils or adhesive pads, so it needs host plants or a support and can smother low shrubs.
Native Range
Native to eastern and northern Australia, from Tasmania and Victoria north through New South Wales and Queensland to the Northern Territory, with related populations in New Guinea. Grows on rainforest margins, in wet sclerophyll forest, and along watercourses in moist, well-drained soils.Suggested Uses
Grown on trellises, fences, and pergolas in shaded and woodland gardens, and in bush-food plantings for its edible tuber. Suits filtered-light positions at 24-36 inch (60-90 cm) spacing along a support. Its twining habit can overwhelm small shrubs, so it is grown on dedicated structures in mixed plantings.How to Identify
Appearance
Size & Dimensions
Height10' - 20'
Width/Spread3' - 6'
Bloom Information
Flowers in summer, mainly December to February in its native range. The small greenish flowers are easily overlooked and last several weeks on slender hanging spikes. Capsules ripen on female plants in autumn.
Detailed Descriptions
Foliage Description
greenGrowing Conditions
Sun Requirements
Requires 3-6 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grows in part shade to filtered light in moist, free-draining soil with added organic matter, climbing on a trellis, fence, or host shrub. Water through spring and summer while stems are in active growth; the plant draws down to its tuber and needs little water once dormant in winter. The tuber resprouts in spring, so dieback of the top growth in cold weather is normal. Hardy where the ground does not freeze deeply; in cold zones the tuber is grown in a container moved under cover. Few pests trouble it, though aphids may gather on soft new shoots. Established tubers can be lifted in winter for division or harvest.Pruning
Dead stems are cut back to ground level in winter once they have yellowed. Stems can be shortened during the growing season to keep the vine within its support. Cutting does not harm the tuber, which carries the plant to the next season.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
winter
Container Growing
✓ Suitable for container growing
Minimum container size: 5 gallons