Notothlaspi viretum Heenan

Perennial herb, with short lateral stems, stems 1.0–1.7 mm diam., usually forming compact cushions of few to numerous rosettes. Leaves 9.0–26.0 mm long, rosulate or spreading on stems; lamina 7.0–17.0 mm long, 0.7–2.4 mm wide, linear to linear-narrowly lanceolate, green, coriaceous, glabrous on abaxial and adaxial surfaces; margin usually entire, occasionally 1-pinnatafid; apex attenuate, tip obtuse with a prominent hydathode, base attenuate; petiole 2.0–10.0 mm long, often indistinct from lamina. Inflorescence axillary, flowers solitary; peduncle 7–10 mm long, 0.4–1.0 mm diam., ascending, glabrous. Sepals 3.7–4.5 mm long, 1.2–1.5 mm wide, linear-lanceolate, green, glabrous, margin entire, apex subacute, base truncate. Petals 5.5–6.5 mm long, 1.6–2.4 mm wide, white, limb obovate to broadly elliptic, patent to reflexed; apex obtuse; base cuneate, tapering to a 2–3 mm long claw. Stamens 6; filaments linear, two 2.4–4.0 mm long, four 3.4–5.4 mm long; anthers 0.9–1.0 mm long, cream to pale yellow. Ovary 2.2–3.0 mm long, 1.2–1.8 mm wide, compressed, green, glabrous; ovules 5–8 per locule; style 2.0–2.1 mm long, terete; stigma capitate, 0.4–0.5 mm diam. Silicle 4.3–5.2 mm long, 4.5–5.1 mm wide, green, glabrous, obcordate, angustiseptate; valves keeled, winged, wing c. 0.5 wide at base, up to 2.3 mm wide at apex, wing extended to form an apical notch to silicle; style persistent, up to 1.2 mm long. Seeds 0.8–1.1 mm long, 0.6–0.9 mm wide, orbicular-oblong, brown. Chromosome number 2n = 90–100.

© Magnolia Press. Reproduced from Heenan 2019  (Phytotaxa 399 (3): pages 256–257) with permission from Magnolia Press.

Notothlaspi viretum occurs among rocky outcrops, on open, sparsely vegetated, stable to semi-stable scree, coarse sand, and soil derived from ultramafic harzburgite rock at an elevation of 1540–1700 m (Heenan 2019).