Tanacetum parthenium (L.) Sch.Bip.

Strongly aromatic perennial herb, not rhizomatous. Stems erect, 20–60 cm tall, ribbed, sparsely to moderately clothed in short hairs especially above, not branched or much branched from base. Basal lvs petiolate, ovate to ovate-oblong, sparsely to moderately clothed in short hairs and with scattered pitted glandular hairs, 1-pinnate with leaflets again 1–2-pinnatisect, 3–15 × 2–6 cm; primary leaflets in 3–5–(8) pairs, ovate, all in one plane, shortly petiolulate at base of lf; ultimate segments ovate to oblong, crenate or serrate. Cauline lvs similar to basal, but above becoming shortly petiolate, smaller and less divided, usually with numerous glandular hairs on lower surface. Corymb with 8–40–(50), loosely packed capitula. Involucral bracts sparsely hairy, 2–4–(5) mm long; margin pale, membranous, especially at apex. Capitula 15–30 mm diam.; ray florets 12-numerous; ligules white; disc florets usually numerous, yellow, few in double forms. Achenes c. 1.5 mm long, pale brown, glandular, ribbed; corona lobed, c. 0.2 mm long.

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

Flowering: Nov.–Jun.