Constant species

Anchusa arvensis, Bilderdykia convolvulus, Chenopodium album, Descurainia sophia, Elymus repens, Polygonum aviculare, Reseda lutea.

Physiognomy

The Descurainio-Anchusetum is an ephemeral community in which Descurainia sophia, probably a long-established introduction (Rich 1991), Anchusa arvensis and Reseda lutea comprise a distinctive group of constants, along with very frequent Elymus repens, Chenopodium album, Polygonum aviculare and Bilderdykia convolvulus.

Also very common are Veronica persica, V. polita, Chamomilla suaveolens, Matricaria perforata, Stellaria media, Senecio vulgaris, Solanum nigrum, Silene alba and Colvolvulus arvensis. More distinctive occasional include Erodium cicutarium, Conyza canadensis, Urtica urens, Papaver rhoeas and Linaria vulgaris with the grasses Poa annua, Agrostis capillaris, A. stolonifera and Dactylis glomerata.

Habitat

The Descurainio-Anchusetum is characteristic of disturbed, dry, sandy soils among arable crops in the Continental climate of East Anglia.

D. sophia is perhaps not native to Britain (Rich 1991, Stace 1995) but it is long established and was formerly, according to Salisbury (1964), much more common than now as a plant of waste ground. It remains frequent among arable crops in East Anglia from where Silverside (1977) characterised this assemblage on soils derived from superficials over chalk, reasonably calcareous, often sandy, though not always rapidly draining. Even in the very dry climate of Breckland, where the community was especially distinctive, the soils could be moist, particularly where irrigation was frequent. Anchusa arvensis, Reseda lutea and Veronica polita are three other species here which reflect the combination of light soils in a more Continental climate typical of the community.