Cornflower (Centaurea cyanus)

KingdomPlantae
PhylumAnthophyta
ClassMagnoliopsida
OrderAsterales
FamilyAsteraceae
GenusCentaurea
SizeStem height: 20-50 cm

Classified as Endangered in the UK, and protected under Schedule 8 of the Wildlife and Countryside Act (as amended) in England and Wales.

The attractive flowers of the cornflower are a bright celebratory blue, distinctive enough to have given its name to a colour. The narrow grey-green leaves, no more than five millimetres wide, grow alternatively up the stem. The closed, emerging flower heads resemble other members of the knapweed family to which the cornflower is closely related.

In the early years of the twentieth century, cornflowers were common in Britain and, together with red poppies and white-flowering Mayweed, must have made a patriotic sight across parts of the countryside.

Although it has declined in north-western Europe, the cornflower is not considered a threatened species in Europe as a whole, and its stronghold is in the Mediterranean countries. However, in Britain there is now only one persistent and self-sustaining population, in Suffolk, although there are recent records from arable fields in Wiltshire, Buckinghamshire and Lincolnshire. There are scattered plants throughout southern England and Wales although it is thought that most of these may originate from wildflower seed mixtures and do not last for many years.

Cornflower is a plant of arable fields and sandy loam soil. It was often found growing in association with corn marigold Chrysanthemum segetum.

Cornflower is an annual plant that flowers between May and August. The seed usually germinates the following spring but it can remain viable for many years. This explains why in the later years of the twentieth century it made unexpected reappearances along road-building projects, triggered into germinating by the disturbance of the earth.

In another location, College Lake Nature Reserve at Pitstone in Buckinghamshire, the warden discovered soil dating from the 1930s and before the age of herbicide. He spread it over a field at the edge of the reserve and the dormant seeds of cornflower, corncockle Agrostemma githago and pheasant's eye Adonis annua all germinated.

Along with many other farmland plants, cornflower has suffered through the increasing industrialisation of agriculture. The use of pesticides and fertilisers, destruction of field edges, conversion to improved pasture and development of competitive crop varieties have resulted in the decline or loss of many of our so-called arable weed species.

The cornflower is listed under the UK Biodiversity Action Plans and included in English Nature's Species Recovery Programme. It is also part of Plantlife's 'Back from the Brink' project.

The most urgent tasks to preserve this plant are to maintain its current range and manage viable populations on all the present sites. Seed has been collected and stored at the Millennium Seed Bank at Wakehurst Place, part of the Royal Botanic Gardens, Kew. This seed may be used for ex-situ propagation and a reintroduction programme if this becomes necessary.

It is also important that the cornflower's plight is publicised, along with many other farmland plants in danger of disappearing through intensive agricultural practise. These other plants include interrupted brome, Deptford pink and purple ramping fumitory.

See also:
http://www.plantlife.org.uk

Information supplied by English Nature.
http://www.english-nature.org.uk