Arabis alpina |
Arabis blepharophylla |
|
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alpine rockcress, arabis alpina |
coast rock cress, rose rockcress |
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Habit | Perennials; (stoloniferous, with vegetative rosettes, loosely cespitose to somewhat pulvinate); sparsely to moderately pubescent, trichomes stalked, cruciform, stellate, mixed with simple and forked-stalked ones. | Perennials; (caudex simple or branched, covered with persistent petiolar remains); sparsely to moderately pubescent, trichomes simple, forked-stalked, or rarely cruciform or 3-rayed, stalked, stellate. |
Stems | usually simple from base, erect to ascending, often branched proximally, (0.6–)1–2(–2.5) dm. |
simple or few from base (caudex), erect, unbranched or branched (few) distally, 0.6–2.5(–3) dm, (usually pubescent throughout, rarely subglabrate). |
Basal leaves | petiole 0–1 cm; blade spatulate, oblanceolate, oblong, or obovate, (0.4–)1–4(–5) cm × (3–)6–15(–20) mm, margins dentate to denticulate, apex obtuse or acute, surfaces usually pubescent, rarely subglabrate, trichomes stellate with simple rays. |
petiole 0.5–3(–6) cm, (ciliate); blade oblanceolate, spatulate, or obovate, (1.5–)2.1–3.5(–6) cm × (5–)8–20(–25) mm, margins entire or dentate, (ciliate), apex obtuse, surfaces pubescent or glabrous, trichomes simple and forked, sometimes mixed with 3- or 4-rayed stellate ones. |
Cauline leaves | 3–5(–6); blade oblong or ovate, 1–3 cm × 5–15 mm, base subcordate or auriculate, margins usually dentate, rarely subentire, apex acute or obtuse. |
(2 or) 3–6 (or 7); blade oblong or ovate, 1–2(–4) cm × (2–)4–10(–15) mm, base not auriculate, margins entire or dentate, (ciliate), apex obtuse, surfaces pubescent as basal leaves. |
Racemes | simple, (lax). |
simple, (dense). |
Flowers | sepals oblong, 2.5–4(–4.7) × 1–2 mm, lateral pair conspicuously saccate basally; petals white, spatulate to obovate, 5–8(–9) × 2–3.5 mm, apex obtuse; filaments 3–5 mm; anthers oblong, 0.7–1.2 mm. |
sepals (purple), oblong, 5–7 × 1.5–2 mm, lateral pair saccate basally; petals purple, spatulate or broadly so, (12–)14–18 × 4–7 mm, apex obtuse or rounded; filaments 6–8 mm; anthers narrowly oblong, 1.2–1.5 mm. |
Fruiting pedicels | ascending to divaricate, 4–10(–12) mm. |
ascending to erect, (3–)5–10(–15) mm. |
Fruits | ascending to spreading, torulose, 1.7–3.5(–4) cm × 1–1.7 mm; valves each with midvein absent or obscure, along proximal 1/2; ovules 34–50 per ovary; style 0.3–0.6 mm. |
erect or nearly so, slightly torulose, 2–4 cm × 2–3 mm; valves each with prominent midvein extending full length or rarely to middle; ovules 20–28 per ovary; style 0.2–1(–1.5) mm. |
Seeds | narrowly winged throughout, ovate, 1–1.4 × 0.9–1.1 mm; wing 0.1–0.2 mm wide. |
narrowly winged throughout, orbicular or suborbicular, 2–2.5 mm in diam.; wing 0.2–0.4 mm wide (wider distally). |
2n | = 16. |
= 16. |
Arabis alpina |
Arabis blepharophylla |
|
Phenology | Flowering Jun–Aug. | Flowering Mar–Apr. |
Habitat | Crevices of limestone rocks, along streams, calcareous alpine meadows, Salix scrub on slopes with scree | Rocky hillsides and bluffs, grassy hillsides, slopes |
Elevation | 0-2400 m (0-7900 ft) | 50-200 m (200-700 ft) |
Distribution |
NY; WA; NL; NU; QC; Greenland; Europe; sw Asia; n Africa; tropical Africa
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CA
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Discussion | Arabis alpina, the generic type, is variable. It is cultivated extensively for its attractive flowers, and it sometimes escapes from cultivation. There is disagreement as to whether one or more species should be recognized in this complex. European, some African, and most North American plants are recognized as A. alpina; most of the larger-flowered, southwestern Asian plants, which are most commonly cultivated, are recognized as A. caucasica or as A. alpina subsp. caucasica (Willdenow) Briquet. In my opinion, the morphological differences between the two (see key, couplet 3) support recognition of two species, as did R. C. Rollins (1993) and G. A. Mulligan (1996). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Arabis blepharophylla is an attractive species on the gradual increase in cultivation as an ornamental. It is recorded from Contra Costa, Marin, San Francisco, San Mateo, Santa Cruz, and Sonoma counties; most of the records are based on older collections. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 7, p. 259. | FNA vol. 7, p. 266. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | A. alpina var. glabrata | |
Name authority | Linnaeus: Sp. Pl. 2: 664. (1753) | Hooker & Arnott: Bot. Beechey Voy., 321. (1838) |
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