Lepidium banksii

Detailed description

Tap-rooted, strongly pungent smelling, perennial herb. Growth habit dense, stems closely placed, 20–50 cm tall. Stems upright to spreading, stout, barely flexuous; mature stems woody, 100–500 × 3–8 mm, often devoid of foliage on middle and lower parts of stems. Leaves glabrous, coriaceous, green, planar, rosette and stem leaves usually withering, variable in size and shape. Leaves of young and vigorous plants and stems: lamina 20–40 × 6–15 mm, oblanceolate-spathulate, obovate; apex obtuse, often with up to 3 or 4 teeth; margin coarsely serrate, with 15–21 pairs of teeth; teeth up to 2.0 mm deep, irregular in size, protruding beyond leaf outline; base attenuate to cuneate, petiole distinct; petiole up to 35.0 × 1.3–2.8 mm, channelled. Leaves of mature plants and cauline stems: lamina 8–25 × 3–6 mm, linear oblanceolate, obovate; apex obtuse to truncate, often with up to 3 or 4 teeth; margin serrate in upper half, up to 7 pairs of teeth; not overlapping, up to 1.5 mm deep, often protruding beyond leaf outline; base attenuate to cuneate, usually tapering to ± distinct petiole, sometimes appearing sessile; petiole up to 8.0 × 1.0–1.8 mm, channelled. Inflorescences terminal and lateral, racemose, 20–80 mm long, rachis 0.6–1.4 mm diameter, glabrous or sometimes with pale clavate hairs; pedicels 5–8 mm long, erecto patent, with pale clavate hairs on adaxial surface, hairs 0.1–0.15 mm long. Flowers 4.0–4.5 mm diameter. Sepals 4, saccate, overlapping at base, green, apex obtuse, margin white, shape and size dimorphic; lateral sepals 1.6–2.1 × 1.1–1.5 mm, orbicular, glabrous; median sepals 1.5–1.9 × 0.9–1.1 mm, broadly elliptic, abaxial surface glabrous or sparsely hairy, hairs 0.2–0.4 mm long. Petals white, 1.8–2.0 × 0.1–0.9 mm, erect, claw indistinct; limb narrowly obovate, elliptic or filiform, often irregular in shape, apex obtuse to subacute. Stamens 4, ± equal lengths, 1.2–1.7 mm long, base 0.6–0.9 mm wide; anthers 0.4–0.7 mm long, yellow or sometimes violet. Ovary 1.4–1.6 × 1.0–1.6 mm, broadly ovate, green, apex round or sometimes weakly shouldered; style 0.2–0.3 mm long, cylindrical below, spreading at apex; stigma 0.45–0.5 mm diameter. Nectaries 4, 0.2–0.4 × c. 0.1 mm, oblong, green. Silicles cartilaginous when fresh, coriaceous when dry, 4.5–5.5 × 4.0–5.0 mm, broadly ovate, apex notched, base cordate, valves green maturing yellow-green, glabrous, slightly winged; style 0.2–0.3 mm long, exserted. Seeds 1.8–2.3 × 1.0–1.2 mm, obovate or obovate-elliptic, brown to orange-brown, not winged.