Common Name: Crown Vetch

General Information

Securigera varia is a herbaceous perennial plant growing from a deep, multi-branched taproot and spreading by means of vigorous, fleshy rhizomes. It produces a cluster of decumbent to ascending, branching stems 30 - 150cm long[, ].
The plant is often used as a ground cover, soil stabilizer and also in soil reclamation projects. Although potentially toxic, it is sometimes harvested from the wild for local use as a medicine. It is sometimes grown as an ornamental, there are some named varieties.
The plant can easily become a weed. It is a weed of cultivated crops within its native range and has escaped from cultivation to become a weed in various other areas, including Australia, Canada and the USA[].

Known Hazards

The whole plant contains a toxic glycoside called coronillin[, , , ]. It is one of the most toxic plants growing in Britain[].
The plant contains beta-nitropropionic acid, a potent neurotoxin. When ingested in any but small amounts it can cause vomiting, diarrhoea, abdominal pain, slow pulse and death[].
Ruminants can eat the plant without problems but, for non-ruminants, it can prove harmful if it comprises more than 5% of the diet[].

Botanical References

Range

Eurasia - western Russia to Spain, east to southwestern Siberia, Turkmenistan, Iran

Habitat

Dry grassy places, railway embankments, roadsides etc[].

Properties

Weed Potential	Yes
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	0.50 m
Growth Rate	Fast
Pollinators	Bees
Cultivation Status	Ornamental, Wild

Cultivation Details

Securigera varia is a plant of the temperate zone, where it is found at elevations up to 900 metres. It grows best in areas where annual daytime temperatures are within the range 15 - 28°c, but can tolerate 10 - 40°c[]. When dormant, the plant can survive temperatures down to about -5°c, but young growth is more tender and can be severely damaged at -1°c[]. It prefers a mean annual rainfall in the range 600 - 800mm, but tolerates 300 - 1,000mm[].
Prefers a sunny position, but tolerant of light shade[]. Grows best in an open, well-drained, fertile calcareous soil[, , , ]. Tolerates poor soils and slightly saline conditions[, ]. Prefers a pH in the range 6 - 7, but tolerates 5 - 8[]. Established plants are drought tolerant[].
A food plant for the caterpillars of many lepidoptera species[].
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[].

Edible Uses

None known

Medicinal

The whole plant, used either fresh or dried is a cardiotonic and diuretic[, , ]. It is used in the treatment of prostrate diseases[].
The crushed plant has been rubbed on rheumatic joints and cramps[].

A decoction of the bark has been used as an emetic[].

The plant contains several medicinally active compounds including coumarins and cardiac glycosides in the seeds, flavonoids in various parts of the plant and an essential oil[].
Aerial parts of the plant have shown antibacterial activity against several species of bacteria including Staphylococcus aureus and Escherichia coli[]
The plant should be used with extreme caution, see the notes above on toxicity[].

Agroforestry Uses:

A good ground cover and soil stabilizer for sunny banks and slopes[, ]. It grows rampantly and should not be grown with plants less than 1.8 metres tall[].
The plant fixes atmospheric nitrogen and can be grown on poor and dry soils - it has been used in reclamation projects for land disturbed by mining and other activities[].
The flowers are a good source of nectar for bees[].

Other Uses

The plant can be used as an insecticide[].
A group of 3-nitropropanoyl-D-glucopyranoses isolated from active fractions of the root have been shown to be toxic when administered orally to the scarab beetle Costelytra zealandica. This New Zealand endemic, commonly known as grass grub, is a prevalent pasture pest[].

Propagation

Seed - best sown in situ as soon as it is ripe. The seed usually germinates in the autumn. Stored seed can be pre-soaked for 12 hours in warm water and then sown in situ in mid spring[]. Germination is best at 15 - 25°c[].
Cuttings of half-ripe shoots with a heel, early summer/July in a frame. Can also be taken in spring[].
Division in early spring[]. Very easy, larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the summer or following spring.