OV4: Chrysanthemum segetum-Spergula arvensis community: Spergulo-Chrysanthemetum segetum (Br.-Bl. & De Leeuw 1936) R. Tx. 1937

Summary

Constant species

Chrysanthemum segetum, Poa annua, Polygonum aviculare, Spergula arvensis.

Physiognomy

The distinctive feature of the annual vegetation of the Spergulo-Chrysanthemetum is the constancy of Spergula arvensis and Chrysanthemum segetum, the latter often abundant and especially striking by summer with its big, bright yellow flower heads. Poa annua and Polygonum aviculare are also constant in the community, Elymus repens, Capsella bursa-pastoris and Stellaria media frequent. Occasional occurring throughout are Bilderdykia convolvulus, Misopates orontium, Euphorbia helioscopa and Chamomilla suaveolens. The perennial grasses Elymus repens and, somewhat less commonly Lolium perenne and Agrostis stolonifera can get a hold each year, though renewed disturbance curtails their continuing growth.

Sub-communities

Typical sub-community. In this sub-community, the only additional distinguishing features are frequent records for Matricaria perforata and occasional Poa trivialis, Polygonum lapathifolium, Fumaria muralis ssp. boraei and Lamium purpureum.

Ranunculus repens-Sonchus asper sub-community. Here, Ranunculus repens and Sonchus asper are strongly preferential with Polygonum persicaria and Potentilia anserina also frequent and occasional records for Anagallis arvensis, Viola arvensis, Myosotis arvensis, Crepis capillaris, Vicia sativa ssp. nigra and the perennials Bellis perennis, Trifolium repens, Holcus lanatus, Cerastium fontanum and Plantago major.

Habitat

The Spergulo-Chrysanthemetum is a widespread community of disturbed, light, fertile acidic soils throughout the British lowlands, and a common feature of both cereal and root crops.