18. Streptanthus gracilis Eastwood, Proc. Calif. Acad. Sci., ser. 3, Bot. 2: 285. 1902; Pleiocardia gracilis (Eastwood) Greene, Leafl. Bot. Observ. Crit. 1: 86. 1904. TYPE: United States, California, Tulare Co., on trail from East Lake to Harrison’s Pass, 1–13 Jul 1899, Alice Eastwood s.n. (holotype, CAS).
Herbs, annual, slender, glabrous throughout, glaucous. Stems (0.6–)1–3.5 dm, erect, often branched about base. basal leaves rosulate, petiolate, oblanceolate to spatulate, 1–7 cm, sinuate to dentate or rarely lobed; middle cauline leaves oblong to ovate, 0.5–3 cm x, 1–5 mm, short petiolate or sessile, auriculate, entire or apically dentate; upper leaves reduced, amplexicaul or auriculate, entire. Racemes bracteate below or between lowermost 1 or 2 flowers, without a terminal cluster of sterile flowers; fruiting pedicels divaricate to ascending, straight or recurved, 3–6 mm, not expanded at receptacle. Flowers: sepals forming slightly urceolate calyx, rose-purple, 4–5 mm, not keeled; petals pinkish, 7–10 mm, spreading; blade 3–5 x 1.5–2.5 mm, not crisped; claw 5–6 mm, narrower than blade; filaments in 3 pairs of unequal length, free; adaxial pair 5–6 mm; abaxial pair 3–4 mm; lateral pair 1.5–2.5 mm; anthers of all stamens fertile, 1.5–2 mm. Fruits 3–7 cm x 1–1.5 mm, ascending, slightly flattened, straight, torulose; valves glabrous, with obscure midvein; gynophore 0.5–3 mm; replum straight; style 0.1–0.5 mm; stigma entire; ovules and seeds 24–52 per fruit. Seeds oblong, 1–1.5 x 0.6–0.9 mm; wing absent or distal, 0.05–0.25 mm.
Habitat: rocky open subalpine or alpine vegetation, often in pockets of weathered granite sand.
Elevation: 2600–3600 m.
Distribution: United States (California/Fresno, Inyo Co., and Tulare counties).