Rhamnus hypochrysa C.K.Schneid.
Common Name: Chinese Buckthorn
Rhamnus utilis is a usually spiny, deciduous shrub or small tree that can grow up to 4 metres tall[
The plant is a major source of the dye known as 'Chinese Green Indigo', which is used as a colouring in foods and for cloth. A high quality dye, it is.harvested from the wild and the plant has also been cultivated for this dyestuff. The seeds are used to obtain a lubricating oil[
Species in this genus contain hydroxyanthracene derivatives which have a stimulant laxative effect upon the body, and many species are used traditionally as laxatives. In small doses, and for short periods, these can be safe and effective, but used over long periods they can weaken the body's natural ability to defecate and can have a range of long-lasting negative effects upon the body, including anaemia, malabsorption, haematuria and weight loss. Large single doses can cause severe purging.
E. Asia - China (Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hebei, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Shanxi, Sichuan, Zhejiang)
Forests, thickets, mountains, hills, grassy slopes; at elevations up to 3,300 metres[
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Succeeds in any reasonably good soil[
]. Requires a well-drained soil in a sunny position[
The species in this genus are notably resistant to honey fungus[
This species is dioecious[
] - both male and female forms will need to be grown if fruit and seed are required.
A green dye obtained from the plant is used as a food colouring.
The flowers are a good source of nectar for bees[
A green dye is obtained from the bark[
]. It is obtained from the leaves[
]. Highly prized for the quality of its green colour, and known as 'Chinese Green Indigo', prior to the advent of synthetic dyes it was used on a wide scale for dyeing cloth and other materials[
The fruit, bark and leaves contain a yellow dyestuff[
All the species of Rhamnus contain a mixture of compounds (mainly rhamnetin, quercitin and rhamnazin) that make a range of good quality dyes. The colour and its intensity depend upon what part of the plant is used as dyeing material (leaves, fruits and bark are most commonly used), at what period of growth it is collected and in what state it is used. With the use of the corresponding mordants (alum, copper and iron vitriols, tin dioxide, chromium, etc.) it is possible to obtain virtually the entire spectrum of colours from lemon-yellow to purple and dark cinnamon-brown, from olive-green to intensive blue and violet[
The dye extracts obtained from the bark, leaves and fruits are suitable for dyeing cottons, silks, woollens, leather, paper and wood. These dyes are often exceptional for their fastness[
An oil obtained from the seed is used as a lubricant[
Seed - best sown in the autumn in a cold frame. Stored seed will require 1 - 2 months cold stratification and should be sown as early in the year as possible in a cold frame or outdoor seedbed. Germination is usually good, at least 80% by late spring. Prick out the seedlings into individual pots when they are large enough to handle, and grow them on in the greenhouse or cold frame for their first winter. Plant them out in late spring or early summer of the following year.
Cuttings of half-ripe wood, mid summer in a frame.
Cuttings of mature wood of the current year's growth, autumn in a frame.
Layering in early spring.