Draba jaegeri

Perennials; (densely cespitose); caudex branched (densely covered with persistent leaves, branches sometimes terminating in sterile rosettes); scapose. Stems unbranched, (0.05–)0.15–0.5(–0.6) dm, hirsute throughout, trichomes simple, 0.1–0.8 mm, and 2–4-rayed, 0.0.5–0.4 mm. Basal leaves (densely imbricate); rosulate; sessile; blade oblanceolate to ovate, 0.4–1.5 cm × 1.5–3.5 mm, margins entire, (ciliate, trichomes simple, 0.3–1.1 mm), surfaces pubescent abaxially with stalked, (2–)4–6-rayed trichomes, 0.1–5 mm, (midvein obscure), adaxially glabrous proximally, sparsely pubescent distally with mostly simple trichomes. Cauline leaves 0. Racemes 3–12(–18)-flowered, ebracteate, slightly elongated in fruit; rachis not flexuous, hirsute as stem. Fruiting pedicels ascending, straight, 2–6(–8) mm, hirsute as stem. Flowers: sepals oblong, 2.5–3 mm, hirsute, (trichomes simple and stalked, 2–4-rayed); petals white, spatulate, 4.5–6 × 1.5–2 mm; anthers oblong, 0.8–1 mm. Fruits ovate to elliptic, plane, slightly flattened, 4–8(–11) × 2.5–4.5 mm; valves pubescent, trichomes stalked (2–)4-rayed, 0.05–0.5 mm; ovules 8–16 per ovary; style (1.2–)2–4(–4.5) mm. Seeds oblong, 1.4–2 × 0.9–1 mm. 2n = 54.

Phenology: Flowering Jun–Aug.
Habitat: Limestone outcrops and gravelly soil
Elevation: 2900-3600 m

Nev.

Discussion

Of conservation concern.

Draba jaegeri is superficially similar to D. hitchcockii, a narrow endemic of the Lost River Range in central Idaho. Both species are cespitose perennials with relatively large, white flowers, and a chromosome number (2n = 54) otherwise unknown in Draba (M. D. Windham 2004). Draba jaegeri is readily distinguished from D. hitchcockii by having fruits pubescent with (2–)4-rayed trichomes, styles (1.2–)2–4(–4.5) mm, fruiting pedicels 2–6(–8) mm, and spatulate petals 1.5–2 mm wide. By contrast, D. hitchcockii has fruits pubescent with mostly simple and 2-rayed trichomes (with 3- or 4-rayed ones), styles (0.8–)1–1.7(–2) mm, fruiting pedicels (2–)4–13(–18) mm, and obovate petals 2–3.5 mm wide. Draba jaegeri is known only from the Charleston Mountains in Clark County.

Selected References

None.

Lower Taxa