Crownvetch (Securigera varia)
Bean Family (Fabaceae)
Coronilla varia, axseed, axwort, hive-vine, trailing crownvetch, trailing crown-vetch.
Origin and Distribution:
Crownvetch is a European species that was introduced into North America in the 1950's as a groundcover. It was mainly planted along highways and on embankments to control soil erosion. However, it spread rapidly and is now naturalized in many locations throughout the northeastern U.S. including fields, roadsides, and waste areas. Crownvetch prefers to grow in full sun but can tolerate many soil types and is especially adept at growing on sloping land.
Crownvetch is a perennial characterized by compound leaves made up 11 or more small leaflets arranged in pairs and pinkish flowers resembling those of peas, beans, or clovers that are grouped into head-like clusters. Stems are long and trail along the ground, forming a tangled mass less than 2 feet tall. Reproduction is by seeds.
Roots form a perennial crown.
Trailing stems are generally branched and hairless.
Leaves are 2 to 4 inches long and consist of 11 or more small leaflets arranged in pairs. Leaflets are broad, oval, and about 1/2 to 3/4 inch long.
Each flower is comprised of a single upper petal (standard) that is predominantly pink and two side petals (wings) that are often white. Flowers are grouped in head-like clusters that are about 1 inch wide.
Fruits and Seeds:
The pods of crownvetch are long and slender and look like miniature pea pods. Each pod contains several seeds. Seeds are smooth, brown and oblong.
Vetches (Vicia spp.) look similar except they have tendrils at the ends of their trailing stems and flowers that are either solitary or grouped in elongated rather than head-like clusters.
Plants flower between June to August. Because it is low-growing, crownvetch does not require mowing. Therefore, it is low maintenance and especially suited as a ground cover for use on sloping land. However, plants establish and spread quickly. Crownvetch inhibits growth of other species by climbing over and shading them. Therefore, do not plant crownvetch where its spread can not be tolerated. Crownvetch will not invade shaded areas and it does not seem to survive cultivation. However, if only partially plowed, it can regenerate from buds on rootstocks. Growth may also be controlled through cautious use of selective herbicides.
The plant and its seeds are considered poisonous in Europe and elsewhere; however, there is little known about the possible toxic nature of the weed.
Facts and Folklore:
Crownvetch has few natural insect predators, which can result in increased invasiveness.
Crownvetch adds nitrogen to the soil and for this reason, it is frequently used to restore strip-mined soils.