Knautia arvensis

Knautia arvensis, commonly called field scabious, is a herbaceous perennial flowering plant in the honeysuckle family Caprifoliaceae and the order Dipsacales, in the genus Knautia, which honors the 17th century German botanist Christian Knaut; the species was originally described by Carl Linnaeus. The plant reaches 25 to 100 centimeters in height, with a basal rosette of leaves, the lowest of which are spear shaped and roughly 300 millimeters long, tapering to smaller leaves higher up the stem, and stems bearing long stiff hairs angled downward; it has a tap root and lacks stipules. Its flattened flower heads carry numerous small florets, each with four stamens and a single notched stigma, and produce nut like, cylindrical, hairy fruits 5 to 6 millimeters long, flowering between May and August. The species favors grassy areas and dry soils, particularly where chalk bedrock is present, and commonly appears on roadsides, field margins and meadows, avoiding heavy soils. Scabious species were historically used to treat scabies and other skin ailments, including sores associated with bubonic plague, giving the genus its common English name.