Trapa japonica
Family: Trapaceae
What it is like
Trapa japonica is a ANNUAL. The species is hermaphrodite (has both male and female organs). Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid and neutral soils. It cannot grow in the shade. It can grow in water.
Height (m): 0
Where it is found
Lakes and ponds all over Japan.
Europe to E. Asia.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
Seed - raw or cooked. Some caution is advised, see the notes above on toxicity.
Seed: includes nuts, cereals, peas and beans.
Medicine
Rating: 0
Other
Rating:
How it is grown
We have very little information on this species and do not know if it will be hardy outdoors in Britain. However, judging by the plants native range, it is likely to succeed outdoors at least in the warmer areas of the country. The following notes are based on the general needs of the genus. An aquatic plant, floating by means of inflated petioles, it succeeds in still or slowly-flowing water requiring a position in full sun and a slightly acidic water with a rich planting medium. Plants require a high summer temperature in order to perform well, they are not frost hardy.
Propagating it: Seed - harvest in late summer and store overwinter in a jar of water in a cold but frost-free place. The seed quickly loses its vitality if it is allowed to become dry. Sow in spring, placing one seed in each pot and submerging them under a few centimetres of water.
Best place to grow: Pond;
Habit: Annual
Hardiness:
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Water
Things to keep in mind
We have no specific information for this species, but the raw seed of several members of this genus contains toxins. However, these are destroyed in the cooking process.