Arabis patens |
Arabis georgiana |
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spreading rockcress |
Georgia rockcress |
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Habit | Biennials or, rarely, perennials; (short-lived, with caudex); usually densely hirsute (at least basally), trichomes simple (to 1 mm), sometimes mixed with stalked, forked ones. | 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. |
Stems | simple or several from base (rosette), erect, often branched distally, (1.8–)2.5–4.5(–5.5) dm, (hirsute at least basally). |
simple or few from base (rosette), erect, unbranched or branched (few) distally, 3–7 dm, (hirsute basally, glabrous distally). |
Basal leaves | petiole (0.7–)2–5 cm; blade usually ovate to oblanceolate, rarely cordate, (0.8–)1.5–3 cm × 5–17 mm, margins dentate or serrate, surfaces sparsely to densely pubescent, trichomes simple or forked. |
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. |
Cauline leaves | (5–)8–20(–27), (overlapping or not); blade ovate to oblong or lanceolate, (2–)3–7.5(–9) cm × (10–)13–25(–35) mm, base amplexicaul, margins usually dentate or serrate, sometimes entire, surfaces hirsute. |
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. |
Racemes | branched. |
often simple. |
Flowers | sepals oblong, 2.5–4.5 × 1–1.5 mm, lateral pair slightly saccate basally; petals white, spatulate, (5–)6–9 × 2–3.5 mm, apex obtuse; filaments 3–5 mm; anthers oblong, 0.8–1.2 mm. |
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. |
Fruiting pedicels | ascending to divaricate-ascending, (7–)10–20(–24) mm, (glabrous or sparsely pubescent). |
erect to erect-ascending, 7–16 mm, (glabrous). |
Fruits | divaricate to erect-ascending, (not appressed to rachis), torulose, 2.2–4.6 cm × 0.8–1.2mm; valves each with prominent midvein extending to middle or full length; ovules 16–28 per ovary; style 0.5–2 mm, (slender). |
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. |
Seeds | narrowly winged distally, oblong, 1–1.6 × 0.6–0.8 mm; wing 0.05–0.1 mm. |
narrowly winged throughout, oblong, 0.9–1.9 × 0.5–0.7 mm; wing to 0.1 mm wide distally. |
Arabis patens |
Arabis georgiana |
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Phenology | Flowering Apr–May. | Flowering Mar–Apr. |
Habitat | Rocky wooded slopes, shady stream banks, limestone ledges and bluffs | Stream banks, roadsides |
Elevation | 0-500 m (0-1600 ft) | 0-200 m (0-700 ft) |
Distribution |
DC; IN; KY; MD; NC; OH; PA; TN; VA; WV
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AL; GA |
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.) |
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Source | FNA vol. 7, p. 262. | FNA vol. 7, p. 261. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Boechera patens | |
Name authority | Sullivant: Amer. J. Sci. Arts 42: 49. (1842) | R. M. Harper: Torreya 3: 88. (1903) |
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