Draba santaquinensis

Biennials or perennials; (short-lived); caudex simple (poorly developed, without persistent leaf-bases); not scapose. Stems usually branched, 1.1–3.4 dm, hirsute proximally, trichomes mostly simple and 2-rayed, 0.2–1.5 mm, pubescent distally, trichomes mostly 2-rayed or 3-rayed, 0.2–1 mm. Basal leaves rosulate; petiole (obscure), ciliate, (trichomes simple and 2-rayed); blade obovate to oblanceolate, 1.6–2.5 cm × 5–10 mm, margins usually entire, rarely denticulate, surfaces pubescent, abaxially with stalked, mostly cruciform trichomes, 0.5–1 mm, adaxially with simple and stalked, 2–4-rayed ones. Cauline leaves usually 1–5; sessile or subsessile; blade oblanceolate to oblong, margins often denticulate, (ciliate proximally, with 2-rayed or 3-rayed trichomes). Racemes 9–25-flowered, ebracteate, elongated in fruit; rachis not flexuous, pubescent, trichomes 2-rayed or 3-rayed. Fruiting pedicels horizontal to divaricate-ascending, usually straight, rarely curved upward, 7–10 mm, pubescent, trichomes 2-rayed or 3-rayed. Flowers: sepals oblong-obovate, 2–3.5 mm, pubescent, (trichomes short to long-stalked, 2–4-rayed, 0.2–0.8 mm); petals yellow (often fading whitish), oblanceolate, 3–5 × 1–1.5 mm; anthers ovate, 0.4–0.5 mm. Fruits narrowly elliptic to slightly falcate, plane, flattened, (7–) 10–16 × (2–) 2.5–3.7 mm; valves pubescent, trichomes short-stalked, 2–4-rayed, 0.2–0.5 mm; ovules 14–22 per ovary; style 0.9–1.2 mm. Seeds oblong, 1.1–1.5 × 0.7–0.9 mm. 2n = 20.

Phenology: Flowering late Apr-early Jun.
Habitat: Limestone outcrops and rocky slopes in mixed conifer communities
Elevation: 1800-2400 m

Utah.

Discussion

Although Draba santaquinensis was included within D. brachystylis by previous authors, I. A. Al-Shehbaz and M. D. Windham (2007) have shown that it is distinct both morphologically and chromosomally. It is currently known only from Utah County (American Fork, Provo, and Santaquin canyons) in north-central Utah.

Selected References

None.

Lower Taxa