Horseshoe Vetch

Appearance

The overall appearance depends on its habitat: sometimes it forms upright clumps of flowers; at other times, it sends prostrate leafy runners over a wide area; sometimes it distributes itself as single flowers. The flowers are small, yellow or sometimes orange/red, and of typical shape for the family Fabaceae: these appear for a period of two weeks around May.

Distribution

''Hippocrepis comosa'' is found in the UK, predominantly in the south.

Habitat

''Hippocrepis comosa'' is a calciole. It is a hardy plant that survives long periods of cold winters and dry summers years after year. Colonies are not harmed by sheep grazing, and are resistant to moderate trampling; they do not thrive after heavy ploughing or disturbance of the ground. In areas grazed by cattle they disappear, sometimes after several years ''Hippocrepis comosa'' is the exclusive food plant of the caterpillars of chalkhill blue and Adonis blue butterflies. Populations that support such butterflies occur on longstanding ungrazed meadows, quarries, edges of paths and wasteland; outside of southern England and the Midlands the climate is unsuitable for the butterflies.

Re-establishment of a colony of ''H. comosa'' is best attempted by planting individual plants: direct sowing has poor rates of success. Even this however offers no guarantee of a permanent colony and even less likelihood that the new plants will be used by significant populations of chalkhill blue butterflies within another 50 years.