Flora of New Zealand Series

knapweed

Perennial. Stems erect, ribbed, simple or branched above, 30-75-(120) cm tall, glabrescent or sparsely hairy with scabrid, multicellular or appressed cobwebby hairs. Lvs not decurrent on stems, with short scabrid hairs; lower lvs narrowly oblanceolate, simple, dentate to pinnatifid, 10-30 × 1.5-3.5 cm, with triangular-oblong, apiculate lateral lobes; upper lvs pinnatifid or entire, becoming sessile, smaller. Capitula not clustered. Involucre globose, (9)-12-18 mm diam.; outer and middle bracts ovate to broadly elliptic or triangular, not or weakly veined, with cobwebby hairs; appendages erect to recurved, pectinate-fimbriate, covering bracts, membranous, conspicuously narrowed at junction of bract, not decurrent on bract; fimbriae 8-16 on each side, brown, 2.5-4 mm long. Florets pink to purple, the outer ± radiate. Corolla eglandular. Achenes c. 2.5-3.5 mm long, sparsely pubescent; pappus 0-0.5 mm long.

N.: Northland, Auckland, Waikato, Bay of Plenty, Hawke's Bay, Wairarapa, Manawatu, Wellington; S.: Nelson, Marlborough, Westland, Canterbury, Otago.

W. and C. Europe 1870

Roadsides, pasture, waste land, grassland, railway lines.

FL Oct-May FT Nov-Jun.

The distinct narrowing of the appendages at their junction with the involucral bracts distinguishes C. nigra from the other spp. naturalised in N.Z. except C. jacea; C. jacea is distinguished by having all the bract appendages lacerate, and usually lyrate-pinnatifid lvs.

C. nigra is treated in a broad sense here and includes some plants with small capitula, pale erect appendages, pale florets and the pappus very short or 0. Such plants are placed in C. debeauxii Gren. et Godron by Dostal, J., in Fl. Europ. 4 (1976), and in C. nigra subsp. nemoralis (Jordan) Gremli, by various authors. Ockendon, D. J., Walters, S. M. and Whiffen, T. P., Proc. Bot. Soc. Brit. Is. 7 : 549-552 (1969), showed that 2 entities could not be distinguished in Cambridgeshire populations because characters varied continuously and were not correlated. Similar patterns of variation are apparent among N.Z. herbarium specimens.