The longan (literally ‘dragon eye’) is a close relative of the lychee, and is one of the most well known and well used of the medicinal fruits in Chinese Medicine. It’s forte is in treating Blood Deficiency, especially in the realm of calming the spirit.
The longan fruits strengthen both the digestive system and also the Heart. As the Heart is the abode of the Spirit in Chinese medicine, this means that the longan is especially indicated for Blood deficiency symptoms involving the mind or emotions – it is one of the favoured medicinal foods for insomnia, poor memory, stress, and palpitations – especially if there are other signs of Blood deficiency (dry skin, floaters in the vision, feeling dizzy when standing)
The Longan fruit is available fresh or tinned in syrup in Chinese supermarkets, or occasionally in the tropical fruit sections of large Western supermarkets. It is also often available dried, in which case it should be a very dark brown / black colour. Avoid dried fruits that are light in colour as they have probably been sulphured to keep them that way.