Herb with stems erect or ascending or creeping at least partially above ground and rarely rooting at nodes, to 30 cm long, rarely rhizomatous, sparsely to densely antrorse-hairy, rarely glabrescent; taproot stout; bulbils absent. Leaves cauline, 3-foliolate; leaflets sessile, cuneate-obcordate, 2–15 mm long and wide, green, bilobed, glabrous to pubescent above, pubescent or hairs confined to midrib below, margins ciliate, sinus to c. two-thirds leaflet length, lobes oblong to obovate, straight, divergent, apices rounded, 2–12 mm apart; petioles usually 1–4 cm long, with antrorse and often spreading hairs; stipules conspicuous, to c. 3 mm long, apex obtuse, rounded or occasionally truncate, ciliate. Inflorescences axillary, flowers (1–)2–3(–6) per peduncle, held well above leaf level; peduncles at least as long as leaves, antrorse-hairy; pedicels usually erect in fruit, sometimes deflexed (but capsules erect). Sepals oblong, 3–5 mm long, often ciliate. Petals 6–12 mm long, yellow. Capsule 8–30 mm long, 1.5–2.5 mm diam., cylindrical, usually densely retrorse-hairy, the hairs simple, patent septate hairs absent; seeds 1.5–2.2 mm long, transversely ribbed, ribs (8–)10–11, narrow, grooves wide, shallow to deep, uniformly coloured, ribs without greyish or whitish lines or blotches. Flowers throughout the year.
LoM, MuM, Wim, GleP, VVP, VRiv, MSB, RobP, MuF, GipP, OtP, WaP, Gold, CVU, GGr, DunT, NIS, EGL, EGU, WPro, HSF, HNF, OtR, Strz, MonT, HFE, VAlp. All States. New Zealand. Widespread in natural to slightly disturbed habitats.
A variable species, possibly containing two (or more) distinct entities. Plants from drier, northern and western parts of the State are of a tufted habit, with a single large taproot, have leaflets that are deeply cleft and narrowly lobed, very long (to 150 mm) peduncles, and fruits that are at least 7 times as long as wide. Plants from higher-rainfall areas of the State are more commonly creeping, have broadly lobed, shallowly cleft leaflets, peduncles mostly to c. 90 mm long, and shorter and broader fruits (less than 7 times longer than wide). Further study is required to determine if this variation requires formal recognition, or is a response to the different habitats. Oxalis perennans may be confused with O. radicosa, but for differences see notes for that species.