Synonymy

Echinochloo-Setarietum (Kruseman & Vlieger 1939) emend. Kruseman & Vlieger apud Sissingh, Vlieger & Westhoff 1940 sensu Silverdale 1977

Constant species

Crepis capillaris, Digitaria ischaemum, Elymus repens, Erodium cicutarium, Geranium molle, Poa annua, Senecio vulgaris, Spergula arvensis, Stellaria media.

Rare species.

Apera spica-venti.

Physiognomy

The rare annual introduced grass Digitaria ischaemum, together with Erodium cicutarium and Spergula arvensis, provide a distinctive group of constants in this Digitaria Erodium annual weed community. Also very frequent are Stellaria media, Poa annua, Senecio vulgaris, Geranium molle, Crepis capillaris and Elymus repens.

Other common associates are Bilderdykia convolvulus, Capsella bursa-pastoris, Rumex acetosella, Papaver dubium, Chenopodium album and Taraxacum officinale agg. Occasionals of the community include Polygonum aviculare, Medicago sativa, Ornithopus perpusillus, Scleranthus annuus, Raphanus raphanistrum and Urtica urens with Holcus mollis and Achillea millefolium sometimes figuring. Bryophytes are occasionally found with Bryum rubens and Pleuridium subulatum most common.

Habitat

The Digitaria-Erodium community is confined to fertilised sandy soils disturbed by the cultivation of root crops and cereals in a very localised part of south-east England.

D. ischaemum is a native of warm-temperate parts of Europe and Asia first recorded in East Anglia in about 1805 and since then locally established among arable crops in sandy fields in southern and south-east England (Hubbard 1984), having probably spread in contaminated seed (Salisbury 1964). It has declined markedly in its occurrences with the shift to more intensive kinds of arable agriculture, although it can persist in situations with quite considerable soil enrichment.