Latin name: Astragalus gummifer
Synonyms: Astracantha gummifera
Medicinal use of Tragacanth:The gum obtained from the root and stem is demulcent, though it is not often used internally because it is not completely soluble. This gum has recently been shown to stimulate the immune system and to suppress tumours. The gum has long been employed externally as a dressing for burns and is also used in lozenges in order to bind the ingredients and impart consistency to the product.
Description of the plant:
(11 3/4 inch)
Habitat of the herb:Dry sub-alpine slopes and valleys, occasionally below the tree line, 1200 - 2600 metres in Iraq. Upland forests and grassland.
Edible parts of Tragacanth:A source of a high quality gum tragacanth - used as a thickener in confections, salad dressings, sauces etc. It is an approved additive to food and has the E number E413. Some of the gum exudes naturally from the root and from damaged stems, more can be obtained by incision of the stem about 5cm below ground level.
Other uses of the herb:Gum tragacanth is obtained from the stem (see above). It has a wide range of uses including:- a thickening agent in preparing dyes for calico printing, textile dyes and for dressing fabrics, it is also a thickener in making glues, water colours, ink (where it supplies a gloss), it is a binding agent in paper making, a culture medium in laboratories etc. Both the stems and the gum can be burnt as a fragrant incense.
Propagation of Tragacanth:Seed - best sown as soon as it is ripe in a cold frame. A period of cold stratification may help stored seed to germinate. Stored seed, and perhaps also fresh seed, should be pre-soaked for 24 hours in hot water before sowing - but make sure that you do not cook the seed. Any seed that does not swell should be carefully pricked with a needle, taking care not to damage the embryo, and re-soaked for a further 24 hours. Germination can be slow and erratic but is usually within 4 - 9 weeks or more at 13°C if the seed is treated or sown fresh. As soon as it is large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter, planting them out into their permanent positions in late spring or early summer, after the last expected frosts.
Cultivation of the herb:Dry sub-alpine slopes and valleys, occasionally below the tree line, 1200 - 2600 metres in Iraq. Upland forests and grassland.
Known hazards of Astragalus gummifer:Many members of this genus contain toxic glycosides. All species with edible seedpods can be distinguished by their fleshy round or oval seedpod that looks somewhat like a greengage. A number of species can also accumulate toxic levels of selenium when grown in soils that are relatively rich in that element.
Plant information taken from the Plants For A Future.