Ground Plum, Groundplum milkvetch
Astragalus crassicarpus

Family: Fabaceae or Leguminosae

What it is like

Astragalus crassicarpus is a PERENNIAL growing to 0.5 m (1ft 8in). See above for USDA hardiness. It is hardy to UK zone 7. The species is hermaphrodite (has both male and female organs) and is pollinated by Bees, Lepidoptera (Moths & Butterflies). It can fix Nitrogen. It is noted for attracting wildlife. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers dry soil.

Height (m): 0.5

Where it is found

Prairies and plains.

Western N. America - Eastern Rocky mountains and eastward to Nebraska.

Conservation Status:

Countries/locations it is found in

Canada, Kuwait, North America, USA. The USDA database lists Astragalus crassicarpus (groundplum milkvetch ) as native to some of the L48 (Lower 48 States), and Canada. Native to North American prairies but not the eastern forest region.

How it is used

Food

Rating: 4

The thick fleshy unripe seedpods, which resemble green plums, are eaten raw or cooked. They are highly esteemed. The pods are about 25mm in diameter.

Seedpod: things such as Okra, French and Runner beans.

Medicine

Rating: 1

A compound decoction or infusion of the root has been used to treat fits and convulsions and has been used on bleeding wounds. It has also been taken or used externally as a stimulant.

Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.

Haemostatic: Controls internal bleeding.

Stimulant: Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.

Other

Rating: 3

Nitrogen Fixer. Provides shelter for beneficial invertebrates: insects and other arthropods. A general nectary plant.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

Nitrogen Fixer: Plants that fix nitrogen in the soil

How it is grown

Requires a dry well-drained soil in a sunny position. Plants are intolerant of root disturbance and are best planted in their final positions whilst still small. The stems are sometimes prostrate. This species is somewhat polymorphic and is separated into a number of distinct species by some botanists. The form sometimes known as A. mexicanus has larger seedpods than the type, up to 35mm in diameter. 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. For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. The plant growth habit is a clumper with limited spread. The root pattern is rhizomatous with underground stems sending roots and shoots along their length.

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: 6-9

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.

Its other names

Local names

Ground plum, Buffalo bean, Groundplum milk-vetch, Buffalo pea.

Synonyms

A. caryocarpus. Ker-Gawl. A. mexicanus. A. succulentus. Geoprumnon succulentum.