Arabis georgiana |
Arabis blepharophylla |
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Georgia rockcress |
coast rock cress, rose rockcress |
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Habit | Biennials; sparsely to moderately hirsute (at least basally), trichomes simple, mixed with fewer, short-stalked, forked ones, subsessile cruciform or 3-rayed stellate trichomes commonly on abaxial blade surfaces, sometimes plants glabrous distally. | 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 | simple or few from base (rosette), erect, unbranched or branched (few) distally, 3–7 dm, (hirsute basally, glabrous distally). |
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 0.5–2 cm, (ciliate or not); blade spatulate, oblanceolate, or obovate, 1.5–6 cm × 5–15 mm, margins dentate, apex obtuse or acute, abaxial surface moderately to sparsely pubescent, trichomes subsessile stellate, adaxial surface subglabrate or sparsely stellate. |
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 | 7–26; blade oblong, lanceolate, or linear-lanceolate, 1.5–7 cm × 3–18 mm, base auriculate to subamplexicaul, margins dentate or entire, apex acute or obtuse, pubescent as basal leaves except distalmost leaves often glabrous. |
(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 | often simple. |
simple, (dense). |
Flowers | sepals oblong, 2.5–4.5 × 1–1.5 mm, lateral pair subsaccate basally; petals white, narrowly spatulate or oblanceolate, 6–9 × 1–1.5 mm, apex obtuse; filaments 3–4.5 mm; anthers oblong, 0.8–1 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 | erect to erect-ascending, 7–16 mm, (glabrous). |
ascending to erect, (3–)5–10(–15) mm. |
Fruits | erect to erect-ascending, (often subappressed to rachis), smooth, 4–7 cm × 0.7–0.8 mm; valves each with midvein extending full length or to middle; ovules 38–44 per ovary; style 0.7–1.8 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, oblong, 0.9–1.9 × 0.5–0.7 mm; wing to 0.1 mm wide distally. |
narrowly winged throughout, orbicular or suborbicular, 2–2.5 mm in diam.; wing 0.2–0.4 mm wide (wider distally). |
2n | = 16. |
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Arabis georgiana |
Arabis blepharophylla |
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Phenology | Flowering Mar–Apr. | Flowering Mar–Apr. |
Habitat | Stream banks, roadsides | Rocky hillsides and bluffs, grassy hillsides, slopes |
Elevation | 0-200 m (0-700 ft) | 50-200 m (200-700 ft) |
Distribution |
AL; GA |
CA
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Discussion | Of conservation concern. Arabis georgiana is most closely related to A. pycnocarpa, from which it is easily distinguished by having narrower fruits, longer petals, and subsessile cruciform or 3-rayed trichomes on abaxial surfaces of basal leaves. It is known only in Alabama from Bibb and Elmore counties and in Georgia from Stewart County. (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. 261. | FNA vol. 7, p. 266. |
Parent taxa | ||
Sibling taxa | ||
Name authority | R. M. Harper: Torreya 3: 88. (1903) | Hooker & Arnott: Bot. Beechey Voy., 321. (1838) |
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