WildBristol.uk - Discovering Wildlife in Bristol

Stace 4:

Centaurea cineraria L. - Silver Knapweed.

Erect to spreading silvery-tomentose perennial to 80cm, often woody at base; leaves more or less pinnate with narrow segments; phyllaries with blackish-brown, decurrent, deeply toothed apical portion; capitula more or less discoid; phyllaries very like those of C. cyanus in size and form; corolla redish-purple; (2n=18). Neophyte-survivor; on low maritime cliffs and walls below gardens; Branksome (Dorset), Alderny; Italy. Vegetativey closely resembles Jacobaea maritima.

Key:

• Leaves usually deeply lobed, rarely simple and entire, not decurrent on stem; scarcely rhizomatous; flowers usually reddish-purple
• Leaves silvery-tomentose; outer flowers scarcely longer than inner ones (capitula more or less discoid)