Leptinella pyrethrifolia (Hook.f.) D.G.Lloyd & C.J.Webb

A creeping perennial herb forming ± discrete patches us. less than 1 m wide. Rhizomes on the soil surface or intertangled and lying on old decaying rhizomes, stout, 1-3 mm diam., dark and sparsely pilose, becoming woody and glabrous; branches us, clustered, up to 6 radiating from around a flowering node; leaves clustered at apex, but under better conditions older leaves up to 3 cm apart. No short shoots. Roots ± extensive and stout, up to 20 cm long and 1 mm diam. Leaves 1-pinnatifid, occ. simple, 0.5-4.0 × 0.3-1.0 cm (only ca. 1 mm wide if simple); blade 0.4-1.5 cm long, elliptic to obovate or broadly so, coriaceous, thick, dark green, glabrous, midrib not raised on ventral surface; pinnae 1-5 pairs, distant, cut to midrib, obovate, obtuse; teeth us. 0, occ. 1 on either side of larger pinnae, cut 1/3—½ across pinna, triangular. Peduncles longer than leaves, 2-12 cm, us. with 1-8 evenly spaced small linear bracts, occ. nude, sparsely pilose. Occ. monoecious, us. subdioecious with pistillate, staminate and bisexual heads common. Pistillate heads 0.5-1.5 cm diam.; surface flat or slightly convex; involucre hemispherical; phyllaries 20-110 in 2 or more subequal rows, oblong, dark green, with a single dark vein ± evident, glabrous, with wide brown scarious margin, not growing after anthesis; florets 50-300 in numerous rows, 2.75-4.0 mm long, straight, white; corolla 2-4 times as long as wide, with equal teeth. Staminate heads larger, 0.5-1.8 cm diam.; surface convex; involucre spreading or flat; phyllaries 10-60; florets us. fewer, 40-300, occ. with a dark stripe down the broader part of the corolla. Bisexual heads intermediate; in subdioecious populations with all possible percentages of pistillate and staminate florets; in monoecious populations with 15-60 pistillate florets surrounding 50-90 staminate florets. Achenes up to 2.3 × 1.0 mm. ± compressed, biconvex, golden-brown or dark brown, scarcely wrinkled. Flowers in summer.

[Reproduced from Lloyd (1972, New Zealand J. Bot. 10: 277–372, as Cotula purethrifolia Hook.f.) with permission from The Royal Society of New Zealand.]