Draba incerta

Payson

Amer. J. Bot. 4: 261. 1917.

Endemic
Synonyms: Draba exalata E. Ekman Draba incerta var. laevicapsula (Payson) Payson & H. St. John Draba incerta var. peasei (Fernald) Rollins Draba laevicapsula Draba peasei
Treatment appears in FNA Volume 7. Treatment on page 313. Mentioned on page 276, 278, 282, 283, 286.

Perennials; (cespitose, often pulvinate); caudex branched (dense with persistent leaf remains, branches sometimes terminating in sterile rosettes); scapose. Stems unbranched, (0.2–)0.4–1.4(–2.1) dm, often pubescent throughout, sometimes glabrous distally, trichomes often simple and 2–5-rayed, 0.1–0.5 mm, (sometimes with mostly subpectinate ones). Basal leaves rosulate; petiolate; petiole (0–1 cm), ciliate throughout; blade narrowly oblanceolate to linear, (0.4–)0.6–1.7(–2.5) cm × (1–)1.5–3.5(–5) mm, margins entire, (ciliate, trichomes usually simple, rarely 2-rayed, 0.2–1.1 mm), surfaces usually pubescent with short-stalked, pectinate trichomes, 0.15–0.5 mm, sometimes also with 4–6-rayed ones, (midvein usually obscure abaxially), sometimes glabrous adaxially. Cauline leaves usually 0 (or 1, as a bract); sessile; blade linear to oblong, margins entire, surfaces pubescent as basal. Racemes 3–14(–30)-flowered, usually ebracteate, rarely proximalmost flowers bracteate, elongated in fruit; rachis not flexuous, glabrous or pubescent as stem. Fruiting pedicels ascending, straight, (2.5–)4–11(–27) mm, glabrous or pubescent, trichomes 2–5-rayed or pectinate. Flowers: sepals broadly ovate, 2.5–3.5(–4) mm, pubescent, (trichomes simple and 2- or 3-rayed); petals yellow (fading white), oblanceolate to obovate, 4–6 × 1.5–2.5 mm; anthers ovate, 0.3–0.5 mm. Fruits broadly ovate to lanceolate, plane, flattened, 5–9(–11) × 2–4 mm; valves glabrous or puberulent, trichomes simple and 2-rayed, 0.05–0.3 mm; ovules 8–16(–20) per ovary; style 0.2–0.9 mm. Seeds oblong, 1.1–1.5 × 0.7–1 mm. 2n = 112.


Phenology: Flowering Jun–Aug.
Habitat: Rock outcrops, talus, gravelly areas, tundra
Elevation: 0-3300 m

Distribution

V7 414-distribution-map.gif

Alta., B.C., Que., Yukon, Alaska, Colo., Idaho, Mont., Nev., Utah, Wash., Wyo.

Discussion

Draba incerta was shown by G. A. Mulligan (1972) to be sexually reproducing and 14-ploid with x = 8. It is often confused with the apomict D. oligosperma (2n = 32, 64). Draba incerta is readily separated from D. oligosperma by having well-formed (versus abortive) anthers and pollen, stalked (versus sessile) leaf trichomes, and ciliate (versus non-ciliate) basal leaves with obscure (versus prominent) midveins. Although both species have leafless scapes, one often finds a bract adnate to, or subtending, the proximalmost pedicel in D. incerta.

Draba incerta is found near sea level in Alaska.

Selected References

None.

Lower Taxa

None.
... more about "Draba incerta"
Ihsan A. Al-Shehbaz +, Michael D. Windham +  and Reidar Elven +
Payson +
Alta. +, B.C. +, Que. +, Yukon +, Alaska +, Colo. +, Idaho +, Mont. +, Nev. +, Utah +, Wash. +  and Wyo. +
0-3300 m +
Rock outcrops, talus, gravelly areas, tundra +
Flowering Jun–Aug. +
Amer. J. Bot. +
Draba exalata +, Draba incerta var. laevicapsula +, Draba incerta var. peasei +, Draba laevicapsula +  and Draba peasei +
Draba incerta +
species +