Astragalus exscapus
Family: Fabaceae or Leguminosae
What it is like
Astragalus exscapus is a PERENNIAL growing to 0.3 m (1ft). See above for USDA hardiness. It is hardy to UK zone 5. It is in flower from July to August. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, Lepidoptera (Moths & Butterflies). It can fix Nitrogen. Suitable for: light (sandy) and medium (loamy) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers dry soil.
Height (m): 0.3
Where it is found
Steppe and foothills, on limestone soils.
C. Europe - Moldavia and the Ukraine.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 0
Medicine
Rating: 1
A decoction of the plant has been used in the treatment of syphilitic sores.
VD: Used in the treatment of venereal disease
Other
Rating: 2
A gum called morea 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.
Nitrogen Fixer: Plants that fix nitrogen in the soil
How it is grown
Requires a dry well-drained soil in a sunny position. Succeeds in poor soils. Plants are intolerant of root disturbance and are best planted in their final positions whilst still small. This plant is a sub-shrub and although it produces woody stems these tend to die back almost to the base each winter. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby. Many members of this genus can be difficult to grow, this may be due partly to a lack of their specific bacterial associations in the soil.
Propagating it: 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.
Best place to grow: Cultivated Beds;
Habit: Perennial
Hardiness: 4-8
Growth:
Soil: Light (sandy), medium
Shade: No shade
Moisture: Dry
Things to keep in mind
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.