Knautia arvensis

Knautia arvensis
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Dipsacales
Family:	Caprifoliaceae
Genus:	Knautia
Species:	K. arvensis
Binomial name
Knautia arvensis (L.) Coult.

Knautia arvensis, commonly known as field scabious, is a species in the genus Knautia.

It is a perennial plant that grows between 25 and 100 cm. It prefers grassy places and dry soils, avoiding heavy soils, and flowers between July and September. The flowered head is flatter than similar species devils bit scabious and small scabious. There are 4 stamens in each flower, and 1 notched long stigma.

The fruit is nut like, cylindrical and hairy, 5–6 mm in size.

It has a tap root. The stem has long stiff hairs angled downwards. There are no stipules.

The leaves form a basal rosette, are paired on the stem, the lowest typically 300 mm long, spear shaped, whereas the upper are smaller.

It is occasionally used by the marsh fritillary as a foodplant instead of its usual foodplant of devils bit scabious (Succisa pratensis). It is also the foodplant of the narrow-bordered bee hawk-moth (Hemaris tityus).

Name

Species of scabious were used to treat scabies, and many other afflictions of the skin including sores caused by the bubonic plague¹. The word scabies comes from the Latin word for "scratch" (scabere). Another name for this plant is gipsy rose³. The genus Knautia is named after a 17th-century German botanist, Christian Knaut.

Habitat

Commonly found on roadsides and field margins, it is particularly abundant where there is chalk bedrock.

• 
• 
  with Aphantopus hyperantus
• 
• 
• 
  leaves
• 
  Young fruit
• 
  basal leaf - note that in this species it is lobed, whereas Devils Bit scabious it is not
• 
  In Belarus

References

1. Kingfisher Field Guides - Wild Flowers of Britain and Northern Europe
2. Usborne Spotter's Handbook of Birds, Trees, Wildflowers
3. The I-Spy Guide to Wild flowers by Michelin