Nasturtium microphyllum Boenn. ex Rchb.

Perennial stoloniferous herb. Stems trailing, glabrous, up to 1 m long. Lvs glabrous, all similar but becoming smaller near infl., pinnate, petiolate, 2–10–(25) × 1–5 cm; basal auricles very small; leaflets rounded, ovate; margins entire or sinuate. Pedicels glabrous, slender, erecto-patent, spreading to deflexed at fruiting, (8)–12–20–(30) mm long. Sepals 2.5–3.5 × 1 mm. Petals white, (4)–5–6 × 1.5–2.5 mm. Silique glabrous, narrow-oblong to linear, curved, (10)–15–25–(30) × c. 1.5 mm; valves with distinct midrib at least below; style c. 1 mm long. Seeds in ± 1 row per locule, brown, c. 1 mm long, reticulate with 100–150 polygonal depressions per face.

[From: Webb et al. (1985) Flora of New Zealand. Volume 4 as Rorippa microphylla (Rchb.) Hylander]