Flora of New Zealand Series

burdock

Plants openly branched, 1-1.5 m tall. Stems grooved, with sparse to dense cobwebby eglandular and subsessile glandular hairs, rarely glabrous or farinose. Basal lvs deltoid to broadly deltoid, green and sparsely hairy above, whitish and densely felted beneath, (15)-25-40-(55) × (10)-13-30-(35) cm; base cordate; apex subacute to obtuse; margin crenate to bluntly dentate with apiculate vein endings; petioles hollow. Upper lvs similar to basal, becoming smaller. Infl. racemose; peduncles 0-1-(3) cm long. Capitula (12)-15-20 × (14)-20-30 mm. Involucral bracts straw yellow, greenish or purplish, glabrous or with sparse to dense cobwebby hairs; margins with short, stiff, tapered, forwardly directed denticles, at least on the innermost bracts. Florets = or > involucral bracts; corolla reddish purple. Achenes 5-7 mm long; pappus 1.5-3.5 mm long.

N.: Auckland, Waikato, Bay of Plenty, Volcanic Plateau, Taranaki, Manawatu, Hawke's Bay, Wellington; S.: Nelson, Marlborough, Canterbury, Otago, Southland.

Europe, W. Asia 1894

Forest margins, waste land, roadsides, creek beds, scrub, pastures, gardens, sheep yards.

FL Jan-Apr FT Feb-May.

Most N.Z. material is referable to A. minus subsp. minus. Several specimens from S. Canterbury and Otago have infls subcorymbose in the upper part and large capitula (20-30 × 30-45 mm), open above at fruiting and often with dense cobwebby involucral bracts. These resemble A. minus subsp. pubens (Bab.) Arènes, but differ in their often green or purplish involucral bracts.

One specimen from Washdyke (CHR 58769, Mason, 15.1.1945) ha small capitula with dense cobwebby hairs, and was identified as A. tomentosum. However it lacks the characteristic glandular pubescence of that sp., and its petioles are hollow, a feature of A. minus. Its identity remains uncertain.