OV1: Viola arvensis-Aphanes microcarpa community

Summary

Synonymy

Teesdalio-Arnoseridetum minimae (Malcuit 1929 R.Tx. (1937) 1950 sensu Silverside 1977

Constant species

Aphanes microcarpa, Poa annua, Rumex acetosella, Viola arvensis.

Rare species

Anthoxanthum aristatum, Briza minor.

Physiognomy

Both Viola arvensis and Aphanes microcarpa are constants in the open annual vegetation of the Viola-Aphanes community, although Poa annua often contributes much of the cover by early summer. The diminutive perennial herb Rumex acetosella is very frequent too, producing its annual tufts of shoots in the gaps among the other plants.

Frequent associates, usually at low cover, include Matricaria perforata, Stellaria media, Veronica arvensis and Polygonum aviculare with Bilderdykia convolvulus, Trifolium dubium, Spergula arvensis, Ornithopus perpusillus, Viola tricolor, Chrysanthemum segetum, Alopecurus myosuroides, Scleranthus annuus and Anagallis arvensis among the more common occasionals. This community also provides a locus for the introduced grass, Anthoxanthum aristatum, originally from the Mediterranean and spreading widely in southern England in the nineteenth century but now extremely rare (Salisbury 1964, Perring & Farrell (1977). Briza minor, another national rarity, has also been recorded here but it is more usually found now in other communities.

Areas of bare ground can have scattered plants of acrocarpous mosses such as Bryum microerythrocarpum, B. rubens, Dicranella staphylina, Ceratodon purpureus, Phascum cuspidatum and Pleuridium subulatum.

Habitat

The Viola-Aphanes community is typically found among arable crops on impoverished base-poor sandy soils in the more Continental eastern parts of Britain. The local occurrence of suitable soils and the prevalence of intensive cereal production make this a very scarce vegetation type now.