Herb: Japanese Horse Chestnut


Latin name: Aesculus turbinata


Family: Hippocastanaceae (Horse-chestnut Family)



Edible parts of Japanese Horse Chestnut:

Young leaves cooked. Some caution is advised on this entry since the leaves are likely to contain toxic saponins (see notes above on toxicity). Seed - cooked. It can be dried, ground into a flour and used as a gruel. The starch is extracted and eaten. The seed is quite large, about 25 - 30mm in diameter, and is easily harvested. Unfortunately it is also rich in saponins and these need to be removed before the seed can be eaten. See also the notes above on toxicity. The following notes apply to A. californica, but are probably also relevant here:- The seed needs to be leached of toxins before it becomes safe to eat - the Indians would do this by slow-roasting the nuts (which would have rendered the saponins harmless) and then cutting them into thin slices, putting them into a cloth bag and rinsing them in a stream for 2 - 5 days. Most of the minerals etc would also have been leached out by this treatment.

Description of the plant:



Plant:
Deciduous
Tree

Height:
20 m
(66 feet)

Flovering:
June

Habitat of the herb:

Mountains, especially in ravines, all over Japan. In deciduous forests, especially in moist slopes along streams.

Other uses of Japanese Horse Chestnut:

Saponins in the seed are a soap substitute. The saponins can be easily obtained by chopping the seed into small pieces and infusing them in hot water. This water can then be used for washing the body, clothes etc. Its main drawback is a lingering odour of horse chestnuts. Wood - weak, nicely grained. Used for house fittings, domestic items etc.

Propagation of the herb:

Seed - best sown outdoors or in a cold frame as soon as it is ripe. The seed germinates almost immediately and must be given protection from severe weather. The seed has a very limited viability and must not be allowed to dry out. Stored seed should be soaked for 24 hours prior to sowing and even after this may still not be viable. It is best to sow the seed with its "scar" downwards. If sowing the seed in a cold frame, pot up the seedlings in early spring and plant them out into their permanent positions in the summer.

Cultivation of Japanese Horse Chestnut:

Mountains, especially in ravines, all over Japan. In deciduous forests, especially in moist slopes along streams.

Medicinal use of the herb:

None known

Known hazards of Aesculus turbinata:

The seed is rich in saponins. Although poisonous, saponins are poorly absorbed by the human body and so most pass through without harm. Saponins are quite bitter and can be found in many common foods such as some beans. They can be removed by carefully leaching the seed or flour in running water. Thorough cooking, and perhaps changing the cooking water once, will also normally remove most of them. However, it is not advisable to eat large quantities of food that contain saponins. Saponins are much more toxic to some creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish.

Plant information taken from the Plants For A Future.