Draba alpina |
Draba inexpectata |
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alpine Draba |
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Habit | Perennials; (cespitose); caudex branched (covered with persistent leaves or leaf remains); scapose. | Perennials; (cespitose); caudex simple or branched (with persistent leaf remains); not scapose. |
Stems | unbranched, (0.3–)0.5–1.7(–2.8) dm, pubescent throughout, trichomes simple and 2-rayed, 0.3–0.8 mm, with 3–5-rayed ones, 0.1–0.3 mm. |
unbranched, 0.1–0.4 dm, pubescent, trichomes 5–10-rayed, 0.05–0.2 mm, and fewer, simple and 2-rayed ones, 0.3–0.6 mm. |
Basal leaves | rosulate; petiolate; petiole base (not thickened), ciliate, (trichomes simple, 0.3–1 mm); blade oblanceolate to obovate or lanceolate to oblong, 0.8–3(–4.5) cm × 2.5–6(–9) mm, margins entire, surfaces abaxially pubescent with stalked, 2–4-rayed trichomes, 0.1–0.5 mm, with simple ones (midvein obscure, not thickened), adaxially glabrous or sparsely pubescent with simple and stalked, 2–4-rayed trichomes. |
rosulate; subsessile; petiole ciliate; blade obovate to oblanceolate, 0.2–0.4 cm × 0.7–1.5 mm, (base sparsely ciliate, trichomes simple and 2-rayed, 0.4–0.6 mm), margins entire, surfaces densely pubescent with subsessile, 6–12-rayed, stellate trichomes, 0.25–0.7 mm. |
Cauline leaves | 0. |
1–3 (or 4); sessile; blade ovate to lanceolate, margins entire or denticulate, surfaces pubescent as basal. |
Racemes | 6–18-flowered, ebracteate, considerably elongated in fruit; rachis not flexuous, pubescent as stem. |
2–5(–8)-flowered, proximalmost 1–3 flowers bracteate, slightly elongated in fruit; rachis not flexuous, pubescent, trichomes 5–10-rayed. |
Flowers | sepals (purplish tinged), narrowly ovate, 2.5–3 mm, pubescent, (trichomes simple and fewer, stalked, 2-rayed); petals bright yellow, narrowly obovate, 3.5–5 × 1.7–2.5 mm; anthers ovate, 0.3–0.4 mm. |
sepals (sometimes persistent), ovate, 1.2–1.7 mm, pubescent, (trichomes simple and branched); petals white, obovate, 2–2.5 × 1–1.2 mm; anthers ovate, 0.1–0.2 mm. |
Fruiting pedicels | ascending to divaricate-ascending, straight or, sometimes, slightly curved upwards, 4–14(–30) mm, pubescent, trichomes simple and 2–4-rayed. |
ascending, straight, 0.7–2(–3) mm, pubescent as rachis. |
Fruits | elliptic, plane, flattened, 6–10 × 2–3 mm; valves glabrous or glabrescent, trichomes simple, (not confined to replum); ovules 12–24 per ovary; style 0.2–0.3 mm (stigma about as wide as style). |
elliptic to lanceolate, slightly twisted or plane, flattened, 3.5–5 × 1.5–2 mm; valves pubescent, trichomes short-stalked, (3 or) 4(–6)-rayed, 0.1–0.2 mm; ovules 16–24 per ovary; style 0.2–0.4 mm. |
Seeds | (pale brown), ovoid, 0.9–1.3 × 0.6–0.9 mm. |
oblong, 0.7–1 × 0.4–0.5 mm. |
2n | = 80. |
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Draba alpina |
Draba inexpectata |
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Phenology | Flowering Jun–Aug. | Flowering Jul–Aug. |
Habitat | Moist tundra and ridges, sand and gravel flats or beaches | Rocky ridges and slopes, on accumulated soil among boulders, subalpine fir and juniper communities |
Elevation | 0-1000 m (0-3300 ft) | 3100-3700 m (10200-12100 ft) |
Distribution |
LB; MB; NU; ON; QC; Greenland; Europe (Finland, Norway, Russia, Sweden)
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UT |
Discussion | The synonymy above includes two North American names overlooked by C. L. Hitchcock (1941) and R. C. Rollins (1993). Draba alpina was broadly delimited by O. E. Schulz (1927) and included 17 varieties, some of which (e.g., corymbosa, oxycarpa, pilosa) are recognized herein as distinct species. The name D. alpina was so misapplied that it was used for any circumpolar or alpine, scapose, yellow-flowered, perennial Draba. Various chromosome numbers (e.g., 2n = 64, 80, 112, 120; S. I. Warwick and I. A. Al-Shehbaz 2006) have been reported for the species. As circumscribed here, it has the narrow distribution outlined above and includes plants with 2n = 80. Reports of the species from Alaska, Canadian Northwest Territories and Yukon, Siberia, eastern Asia, Russian Far East, and the Central Asian republics are either suspect or very unlikely. The entire D. alpina complex (including the above three species, D. glacialis Adams, D. macounii, etc.) is in need of critical molecular, cytological, and morphological study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Draba inexpectata is known from the Uinta Mountains in Summit County. The measurements above are based on the holotype (Franklin 6328) and two of the three paratypes (Franklin 6293, 6331), all at BRY. One paratype (Goodrich 26166, BRY) is a robust, completely sterile plant of uncertain identity and was not used for the description above. Although compared in the original description with Draba lonchocarpa (with which it grows sympatrically), D. inexpectata appears most closely related to D. cana. Draba inexpectata is distinguished from the latter by having stems 1–4 cm, basal leaves non-ciliate, racemes that are 2–5(–8)-flowered and scarcely elongated in fruit, fruits elliptic to lanceolate, 3.5–5 mm, and ovules 16–24 per ovary. By contrast, D. cana has stems (6–)10–30 cm, basal leaves ciliate at the apex, racemes that are (10–)15–47(–63)-flowered and often considerably elongated in fruit, fruits linear-lanceolate or very rarely ovate-oblong, (5–)6–11 mm, and ovules 28–48 per ovary. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 290. | FNA vol. 7, p. 313. |
Parent taxa | Brassicaceae > tribe Arabideae > Draba | Brassicaceae > tribe Arabideae > Draba |
Sibling taxa | ||
Synonyms | D. alpina var. hydeana, D. alpina var. inflatisiliqua | |
Name authority | Linnaeus: Sp. Pl. 2: 642. (1753) | S. L. Welsh: in S. L. Welsh et al., Utah Fl. ed. 3, 272. (2003) |
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