Aesculus are woody plants and they can be four to thirty five meters. Their height depends on species. Aesculus have stout shoots with resinous, buds; opposite, palmately divided leaves, very large and showy insect pollinated flowers, with four or five petals fused into a lobed corolla tube. They start giving flowers after eighty to one hundred and ten days. The fruit is a rich glossy brown to blackish brown nut two to five cm diameter globose with one nut in a green or brown husk but sometimes two nuts together in one husk, in which case the nuts are flat on one side; the point of attachment of the nut in the husk shows as a large circular whitish scar. The husk has spines in some species, spineless in others, and splits into three sections to release the nut. Aesculus are generally fairly problem free, though a recently discovered leaf-mining moth Cameraria ohridella is currently causing major problems in much of Europe, causing premature leaf fall which looks very unattractive. The symptoms can be confused with damage caused by the leaf fungus Guignardia aesculi, which is also very common but usually less serious. Common horse chestnut is also used as a food plant by the sycamore, another species of moth. The nuts contain high concentrations of a saponin-class toxin called aesculin, which is toxic to many animals including humans because it causes destruction of red blood cells. California buckeye Aesculus californica is known to cause poisoning of honeybees from toxic nectar (native bee species not being affected). Other buckeye species are thought to have the same effect, but the toxins are diluted because the trees are not usually abundant enough in any one area. The wood is very pale whitish brown, fairly soft and little-used. Uses include cheap furniture, boxes and firewood.
Following is the list of their species.
- Aesculus chinensis
- Aesculus californica
- Aesculus glabra
- Aesculus hippocastanum
- Aesculus sylvatica
- Aesculus flava
- Aesculus arguta
- Aesculus turbinata
- Aesculus chinensis var
- Aesculus assamica
- Aesculus indica
- Aesculus neglecta
- Aesculus parviflora
- Aesculus pavia