Aesculus californica - Californian Buckeye

Habitat

Exposition

Plein soleil

Humidité

Sol sec à moyen.

Sol

Tous sols. Nécessite un sol drainant.

pH

Sol acide ou calcaire

Rusticité

Zone 7

Habitat originel

Moist stream borders, scrub and the edges of oak and pine woods in canyons and dry slopes below 1200 metres[71, 184, 229].

Origine géographique

Sud-ouest de l'Amérique du Nord - Californie.

Dangers connus

• 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 .
• Les saponines sont beaucoup plus toxique pour certains animaux, comme les poissons; des tribus de pêcheurs en ont traditionnellement mis de grandes quantitié dans les rivières et les lacs pour droguer ou tuer les poissons [K].
• The flowers of this plant are toxic to bees [94].

Comestibilité

• Graines - cuites [22, 46, 63, 92, 94, 95].
• It can be dried, ground into a powder and used as a gruel [2].
• The seed contains about 23% protein and has an agreeable taste [213].
• The seed is large, and can be up to 5cm in diameter [82].
• It is often produced abundantly in the warmer areas of Britain and is easily harvested [K].
• This was the most commonly used Aesculus species in N. America [213].
• 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 [213].
• Most of the minerals etc would also have been leached out by this treatment [K].

Usages médicinaux

• The seed contains saponins and can be used as an expectorant [94].
• The crushed fruit is applied as a salve on haemorrhoids [257].
• A decoction of the bark is used in the treatment of toothache and loose teeth [257].

Autres usages

• The seed is rich in saponins, these are used as a soap substitute [169].
• 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 [K].
• Wood - soft, light, very close grained [82].
• Of no value as a lumber [229].
• The wood was used as friction sticks for making fire by the North American Indians [257].

Culture

• Prefers a deep loamy well-drained soil but is not too fussy [11].
• Requires a position in full sun [200].
• Prefers dry sunny locations [126].
• Although fairly hardy throughout Britain, it grows best in areas where winter temperatures do not fall below -10°c [200].
• A moderately fast-growing and long-lived tree in the wild[229], in Britain it grows best in eastern and south-eastern England .
• Plants thrives at Kew [11].
• Most members of this genus transplant easily, even when fairly large [11].

Propagation

• Seed - best sown outdoors or in a cold frame as soon as it is ripe [11, 80].
• The seed germinates almost immediately and must be given protection from severe weather [130].
• 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 [80, 113].
• It is best to sow the seed with its 'scar' downwards [130].
• 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 .