Classification
 Nomenclature
Scientific Name:
Carduus acanthoides L.
Vernacular Name(s):
Bastard nodding thistle; Plumeless thistle; Tapapa thistle; Welted thistle
 Description

Taprooted biennial. Stems branched above, 1–2 m tall, with usually sparse multicellular or cobwebby hairs, strongly ribbed; wing narrow or interrupted between the deltoid or palmatifid clusters of teeth; spines 5–10 mm long. Lvs narrow to oblong-lanceolate, deeply 1–2-pinnatifid, 5–20–(40) × 1.5–10–(18) cm, glabrous except for sparse multicellular cobwebby hairs on midrib; basal lvs with 5–9 pairs of lobes; lobes palmatifid-dentate; teeth spine-tipped; spines pale, 3–5–(8) mm long. Capitula erect, persistent, (1)–1.5–(2) × 1.5–2 cm, solitary and pedunculate or in sessile or subsessile clusters of 2–4; peduncle 1–1.5–(2) mm diam. Involucre globose, ovoid or hemispheric. Outer and middle involucral bracts linear-acuminate, evenly tapered to erecto- patent spinous tip, without distinct claw and limb, with sparse cobwebby hairs; midvein raised almost to base. Inner involucral bracts linear, puberulent; midvein barely raised in distal 1/2of bract; apex acute, scarious, often pink. Corolla red-purple, pinkish, or white, (12)–14–18 mm long; lobes 5–6 mm long; swelling at throat of tube oblong, > 2 mm long. Achenes pale, ellipsoid, 3–4 × 1.5–2 mm; pappus 11–14 mm long.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

 Biostatus
Exotic
 Phenology

Flowering: (Nov.)–Feb.–Mar.–(Jun.); Fruiting: (Dec.)–Feb.–Apr.–(Jun.)

 Bibliography
Biosecurity New Zealand 2012: Regional Pest Management Strategies Database. http://www.biosecurityperformance.maf.govt.nz/