Typical Aesculus chinensis, described from Beijing, is planted, especially in temple grounds and by houses, and is not known with certainty in a wild state. The plant formerly known as Aesculus wilsonii Rehder is now recognized as the wild form of Aesculus chinensis and is given varietal status as Aesculus chinensis var. wilsonii (Rehder) Turland & N.H.Xia[].

Common Name: Chinese Horse Chestnut

General Information

Aesculus chinensis is a deciduous tree that can grow up to 25 metres tall. The bole can be up to 250cm in diameter[].
The plant is harvested from the wild for local use as a food, medicine and source of saponins.

Known Hazards

Most, if not all, species in this genus are poisonous, containing the glycoside aesculin, the saponin aescin, and possibly alkaloids[].
The seed is rich in saponins. Although poisonous, saponins also have a range of medicinal applications and many saponin-rich plants are used in herbalism (particularly as emetics, expectorants and febrifuges) or as sources of raw materials for the pharmaceutical industry. Saponins are also found in a number of common foods, such as many beans.
Saponins have a quite bitter flavour and are in general poorly absorbed by the human body, so most pass through without harm. They can be removed by carefully leaching 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 raw foods that contain saponins.
Saponins are much more toxic to many cold-blooded 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 and make them easy to catch[].

Botanical References

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Range

E. Asia - southern central China.

Habitat

Broad-leaved forests, near streams in tall shady forests, woods, thickets, mountain and hill slopes, ravines and roadsides at elevations from 600 - 2,000 metres, occasionally to 2,300 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	25.00 m
Growth Rate	Slow
Pollinators	Bees
Cultivation Status	Wild

Cultivation Details

Aesculus chinensis probably prefers a continental climate with its hot summers, cold winters and usually a clear movement from one season to another. The dormant plant is very cold-tolerant, but in more maritime climates it is often tempted to come into growth early and this new growth can easily be damaged by late spring frosts[, ].
Prefers a deep loamy well-drained soil but is not too fussy[].
Seedlings quickly develop a taproot and larger plants can be difficult to transplant[].

Edible Uses

Seed - cooked. It can be dried and ground into a powder and used as a gruel. The seed is quite large, it can be 3cm in diameter, and is easily harvested. Unfortunately it is also rich in saponins, these must be removed before it can be used as a food and this process also removes many of the minerals and vitamins, leaving behind mainly starch. See also the notes above on toxicity.
The following notes apply to Aesculus californica, but are probably also relevant here:-
The seed needs to be leached of toxins before it becomes safe to eat - the native Americans 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[].

Medicinal

The seed is antirheumatic and emetic[, ]. The sweet tasting seed is said to be used in the treatment of contracted limbs that are due to palsy or rheumatism[, ]. It is also used in the treatment of stomach aches[].

Other Uses

Saponins in the seed are used as 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[].

Propagation

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[]. Seedlings develop a large taproot following germination and so, if grown in containers, should be given sufficient root room[]. 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.