Californian Buckeye, California Horsechestnut
Aesculus californica
Family: Hippocastanaceae
What it is like
Bloom Color: Pink, White. Main Bloom Time: Early spring, Late spring, Mid spring. Form: Rounded.
Aesculus californica is a deciduous Tree growing to 12 m (39ft) by 10 m (32ft) at a medium rate. See above for USDA hardiness. It is hardy to UK zone 7 and is not frost tender. It is in flower from July to August, and the seeds ripen in September. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers dry or moist soil.
Height (m): 12
Where it is found
Moist stream borders, scrub and the edges of oak and pine woods in canyons and dry slopes below 1200 metres.
South-western N. America - California.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 3
Seed - cooked. It can be dried, ground into a powder and used as a gruel. The seed contains about 23% protein and has an agreeable taste. The seed is large, and can be up to 5cm in diameter. It is often produced abundantly in the warmer areas of Britain and is easily harvested. This was the most commonly used Aesculus species in N. America. It does, however, contain poisonous saponins (see the notes above on toxicity) and so needs careful preparation before being eaten. The seed needs to be leached of these 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.
Seed: includes nuts, cereals, peas and beans.
Medicine
Rating: 1
The seed contains saponins and can be used as an expectorant. The crushed fruit is applied as a salve on haemorrhoids. A decoction of the bark is used in the treatment of toothache and loose teeth.
Expectorant: Clears phlegm from the chest by inducing coughing.
Odontalgic: Treats toothache (temporary measure only) and other problems of the teeth and gums.
Salve: Soothes and heals damaged skin.
Other
Rating:
The seed is rich in saponins, these 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. Wood - soft, light, very close grained. Of no value as a lumber. The wood was used as friction sticks for making fire by the North American Indians.
Friction sticks: Used for starting fires when there are no matches.
Soap: Plants used directly as a soap substitute.
Wood: A list of the trees and shrubs that are noted for having useful wood.
Scented Plants: Plants noted for their scent
How it is grown
Landscape Uses:Erosion control, Specimen. Prefers a deep loamy well-drained soil but is not too fussy. Requires a position in full sun. Prefers dry sunny locations. Although fairly hardy throughout Britain, it grows best in areas where winter temperatures do not fall below -10°c. A moderately fast-growing and long-lived tree in the wild, in Britain it grows best in eastern and south-eastern England. Plants thrives at Kew. Most members of this genus transplant easily, even when fairly large. Special Features:North American native, Flowers have an unpleasant odor, Blooms are very showy.
Propagating it: 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.
Best place to grow: Woodland Garden Canopy; Secondary;
Habit: Tree
Hardiness: 6-10
Growth: Medium
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Dry, moist
Things to keep in mind
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. The flowers of this plant are toxic to bees.
Its other names
Local names
Synonyms
Pavia californica.