Images: ©Jouko Lehmuskallio
Greater Knapweed
Centaurea scabiosa
- Family: Daisy Family – Asteraceae (Compositae)
- Growing form: Perennial herb.
- Height: 30–100 cm (ca. 12–40 in.)
- Flower: Purple, deeply lobed, funnel-shaped, fairly large outer and small tubular inner florets grouped together into flower-like heads (capitula), 3–5 cm (1.2–2 in.) across. Corolla of 5 fused petals. Calyx modified into a ring of short hairs (a pappus). Stamens 5, anthers united into a tube around the style. Pistil of 2 fused carpels, style solitary, stigma 2-lobed. Capitulum subtended by several whorls of involucral bracts which are oblong with a brownish-black, fringed horse-shoe-shaped appendage. Capitula solitary, terminating stem and branches.
- Leaves: Alternate. Lower leaves stalked, uppermost almost unstalked. Blade elliptic in outline, pinnately or bipinnately narrow-lobed, sometimes upper leaves merely toothed, each lobe terminated by a short bristle.
- Fruit: A brown, short-hairy, flattened cypsela (4.5–5 mm long) crowned by a pappus of short (4–5 mm) brownish hairs.
- Habitat: Dry waysides and meadows, glades, road verges.
- Flowering time: July–September.
The greater knapweed is a perennial with a strong, woody rhizome. The Finnish populations of this species probably are of various origin. On one hand, the species is associated with old agriculture, on the other with recent roads and railways. The occurrences are concentrated around habitation.
The greater knapweed has been used as a medicine against scabies, hence the specific epithet scabiosa. It is a regionally endangered species.
