Flora of New Zealand Series

nodding thistle

Annual or biennial. Stems branched above, (15)-45-75-(250) cm tall, with sparse cobwebby and multicellular hairs below, becoming more densely cobwebby above, ribbed; wing narrow between the deltoid to palmatifid clusters of teeth; spines 2-6 mm long. Lvs narrow-oblong, deeply pinnatifid, (5)-8-18-(40) × 2.5-10 cm, glabrescent or with scattered multicellular hairs especially on midrib and veins; basal lvs with 5-9 pairs of lobes; lobes pinnatifid to palmatifid-dentate; teeth spine-tipped; spines pale, 5-8 mm long. Capitula nodding, persistent, 3-4-(5) × 3-4-(5) cm, solitary; peduncle (0.5)-3-8-(12) cm long, (1)-2-3-(4) mm diam., leafless, not winged, with dense woolly tomentum. Involucre broadly ovoid to depressed-globose. Outer and middle involucral bracts geniculate; claw narrow-oblong, erect; limb lanceolate, usually broader than base, narrowly lanceolate-acuminate, deflexed to spreading, spine-tipped, ciliolate, the outer bracts sparsely cobwebby as well; midvein raised almost to base of limb. Inner involucral bracts linear, puberulent at base and apex; midvein not raised; apex acute, scarious, often purplish. Corolla usually red-purple, rarely white, 18-24 mm long; lobes 6-7-(8.5) mm long; swelling at throat of tube oblong, > 2 mm long. Achenes pale, ellipsoid, 3-4 × 1.5-(2) mm; pappus (12)-15-22 mm long.

N.; S.: throughout except Westland.

N.W. Africa, Europe, Asia Minor 1889

Pasture, roadsides, waste land, lucerne crops, hill country grassland.

FL (Jul)-Nov-Feb-(Jun) FT (Nov)-Dec-May.

C. nutans is a variable sp. in N.Z., but most specimens are referable to C. nutans sens. strict. Some large-headed plants with very wide middle involucral bracts (> 5 mm) nearly match published descriptions of C. macrocephalus Desf., but the corolla in N.Z. plants is not as long, nor are the peduncles spiny.

In Europe also the situation is not clearly resolved. Franco, J. do A., in Fl. Europ.4 : 222 (1976), treated 8 spp. under the C. nutans group, stating "A difficult group in need of further study. Though a few extreme taxa are easily recognized, there is considerable variation in hairiness, lf-size, spine-length, peduncle-diameter, bract width and shape, and corolla-length. This variation is almost continuous and intermediates between taxa can be found."

Plants more or less intermediate between C. acanthoides and C. nutans sometimes occur where both spp. grow together, e.g., at Culverden in N. Canterbury and in parts of Waikato. These have smaller capitula than C. nutans with spreading involucral bracts and leafy peduncles. However the floret and pappus dimensions match those of C. nutans. Hybridism is suspected.