Indian Horse-chestnut

Flower candles from the Himalayas

This species is native to the mountains of northeast Afghanistan, Pakistan, Kashmir and west Nepal. Here in Europe it is an attractive tree of up to 30 m in height growing in parks and requiring full sun. The smooth, grey bark is striking but turns rough and flaky in older trees. The overwintering buds are sticky. In June, when the tree is in full leaf, the flowers open. The individual flowers, which make up the inflorescence (the 'candles' that consist of many flowers), are white with a yellow spot and turn to pink with long, gracefully protruding stamens. The husk, containing the conker, resembles a small pear. The seed, or conker, is larger and darker brown in colour than the common horse chestnut.

In India, soap is made from cooking the seeds after having removed the seed coat because the seeds are rich in saponin, a soapy substance. Before the leaves are shed in autumn they turn a beautiful yellow colour. Indian horse chestnut is not frost hardy, especially when young. This species can be just as stately and monumental in habit as the common horse chestnut. The light white wood of the Indian horse chestnut was once used to make tea chests.
Colonel Henry Bunbury introduced the Indian horse chestnut to England in 1851.

The tree can grow to 30 m in height and bears a smooth, grey bark, which becomes rough and peeling when mature. The overwintering buds are sticky. Leaves have 5-9 dark green, shiny, fairly large leaflets with finely serrated margins. The leaves vary in colour from bronze pink to chocolate brown. It flowers in late June to early July. The large inflorescences are up to 30 cm, sometimes even 40 cm, long and 10 cm wide. The flowers have a tubular calyx with 4 petals. The two uppermost petals are most prominent because of the macula (or stain), which changes in colour from yellow, through orange to pink. The fruits are slightly warty and pear-shaped.

The leaves, flowers and seeds contain aesculin, a toxic substance although there are animals that are immune to it. To render the seeds usable for consumption, they have to be physically broken down, soaked in water and rinsed for several (5-7) days to remove the bitter toxin. They are then dried and ground into flour.

Some truly ancient specimens can be found in Kew Gardens (London, England), whilst another long-lived specimen is growing in the Leiden Botanic Garden.