Rorippa laciniata

Detailed description

Perennial tap-rooted herb, root stock ± woody, suberect to erect, producing one or more leafy, somewhat flaccid rosettes. Leaves 20–150 × 30–50 mm, mostly basal, narrowly elliptic, elliptic to broadly elliptic or rhomboidal, entire or irregularly and sometimes deeply toothed or lobed, lyrate-pinnatifid, or lyrate-pinnatisect, segments broadly to narrowly linear, often deeply toothed, with a terminal lobe and 1–4 pairs of narrow lobes, adaxially dark green to reddish-green, abaxially similar but lighter, glabrous; margin hairy, hairs up to 0.3 mm long; petioles 50–100 mm long, plano-convex, glabrous, margin narrowly winged; cauline leaves absent or few, similar to basal leaves but smaller and narrower. Inflorescence 10–30 or more flowered, 200–800 mm long, dark green to reddish green, glabrous, sprawling to ascending, often flaccid and supported by surrounding vegetation; flowers protogynous, slightly fragrant, up to 5.7 × 3.6 mm. Pedicels 9.2–12.2 mm long, erecto-patent at flowering, spreading at fruiting. Sepals 4, (2.3–)3.8–4.5 × 1.2–1.3 mm, linear-lanceolate, ± subulate, adaxially dark green, yellow-green to reddish green, glabrous; margin entire, thin, white; apex saccate, obtuse. Petals 4, 3.6–5.5 × 1.9–2.3 mm, oblong, white, flushed lavender at senescence, slightly longer than sepals, base cuneate, apex obtuse, claw 0.8–1.2 mm long. Stamens 4; filaments 2.5–4.0 mm long, white; anthers 0.6–0.8 × c. 0.4 mm, yellow, pollen yellow. Ovary 1.8–4.0 mm long, terete, green; style c. 0.5 mm long; stigma c. 0.6 mm diam., capitate to weakly bilobed. Siliques 15–46 × 1.3–1.8 mm, erect to spreading, linear, straight, ± terete, green, dark green to reddish green; valves with inconspicuous midrib fading toward apex; style remnant 0.5–0.8 mm long; seeds in 1 row per locule. Seed 1.3–1.4 × c. 0.9 mm, light orange-brown, slightly winged, testa punctate, spongy when fresh, mucilaginous.