We are following the Flora of China[
] in usung this name, but some other authorities treating this taxon as a subspecies of Amphicarpaea bracteata as Amphicarpaea bracteata edgeworthii (Benth.) H.Ohashi[
Amphicarpa japonica Benth.
Amphicarpaea bracteata edgeworthii (Benth.) H.Ohashi
Amphicarpaea japonica B.Fedtsch.
Amphicarpaea japonica Benth.
Amphicarpaea trisperma (Miq.) B.D.Jacks.
Amphicarpaea trisperma (Miq.) Baker
Falcata comosa japonica (Oliv.) Makino
Falcata edgeworthii (Benth.) Kuntze
Falcata japonica (Oliv.) Kom.
Shuteria anomala Pamp.
Shuteria trisperma Miq.
Amphicarpaea edgeworthii is an annual climbing plant with slender stems 30 - 130cm long. The plant scrambles over the ground, twining into the surrounding vegetation[
The plant is harvested from the wild for local use as a food.
E. Asia - China, Japan, Korea, Himalayas of northern India and Nepal, Vietnam
Woods and shaded places in lowland all over Japan. Mountain slope, road side, field, grassland at elevations of 300 - 3,000 metres[
Requires a moist humus-rich soil in a shady position[
This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[
Seed and seedpods - cooked[
]. The seedpods are harvested when green and used for food[
Two types of seed are produced. The flowers produced near the ground are cleistogamous (they do not open, but self-fertilize to produce a seed) - they produce a pod with a single seed that buries itself just below soil level. Other flowers are produced higher up the stems, these open normally and are fertilized by insects to produce a pod with up to 5 seeds[
In the closely related Amphicarpaea bracteata the subterranean seeds are considerably larger than the others and are nice eaten raw, whilst the seeds produced higher up the stem are cooked[K[.
The growing plant is a good soil cover, helping to prevent erosion and improve the fertility of the soil[
Seed - pre-soak for 12 hours in warm water and then sow in spring in a semi-shaded position in a greenhouse. Germination usually takes place within a few weeks. When large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter, planting them out in late spring or early summer.
Division. We have been unable to divide this plant because it only makes a small taproot. However, many of the seeds are produced under the ground and these can be harvested like tubers and potted up to make more plants.