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Electronic Flora of South Australia species Fact Sheet

Family: Asteraceae
Centaurea nigra

Citation: L., Sp. Pl. 911 (1753).

Synonymy: Centaurea nigrescens

Common name: Black knapweed, hard-heads.

Description:
Perennial herb to 1 m high, with rhizomes; stems ascending, branched, ribbed, scabrous, slightly cobwebby; basal leaves oblanceolate, narrowed at the base, acute, 6-25 cm long, pinnatifid to entire with undulate margins, finely scabrous; cauline leaves lanceolate to oblong, acute, entire or with a few remote teeth, 1-8 cm long, 2-10 mm wide, scabrous-pubescent, sometimes cobwebby on the lower surface.

Capitula solitary; involucre broadly ovoid, 14-18 mm long; bracts ovate, glabrous; appendages obscuring the bracts, 2-3 mm long, deeply pectinate, dark-brown; outer florets erect to patent; corollas pale-purple.

Achenes c. 3 mm long, pale-brown, slightly ribbed; pappus of bristles to 1 mm long.

Published illustration: Parsons (1973) Noxious weeds of Victoria, p. 91.

Distribution:  On roadsides and waste land.

S.Aust.: MU.   Vic.   Native to Europe.

Conservation status: naturalised

Flowering time: most of the year.


SA Distribution Map based
on current data relating to
specimens held in the
State Herbarium of South Australia

Biology: C. pratcrisis Thuill. is apparently a hybrid between C. nigra and C. jacea L. It was recorded in S. Aust. near Sevenhills in 1934 but has not been collected since then.

Author: Not yet available


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