Arabis georgiana
Arabis nuttallii
Georgia rockcress
Nuttall's rockcress
simple or few from base (rosette), erect, unbranched or branched (few) distally, 3–7 dm, (hirsute basally, glabrous distally).
simple or few to numerous from base (caudex), erect or ascending, unbranched, 0.5–2.5(–3.6) dm, (glabrous throughout or pubescent along proximal 1/2, trichomes simple).
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 0.3–2(–3.5) cm, (glabrous or ciliate);
blade narrowly oblanceolate, spatulate, to obovate, 0.4–2(–3) cm × 3–10(–15) mm, margins entire, (ciliate or not), apex obtuse, surfaces glabrous or sparsely to densely pubescent, trichomes simple, rarely mixed with forked ones.
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.
(1 or) 2–5(–7);
blade linear, oblanceolate, oblong, or obovate, 0.5–2.2(–3) cm × 2–8(–12) mm, base not auriculate, margins entire, (sometimes ciliate), apex obtuse, surfaces glabrous or, rarely, sparsely pubescent.
often simple.
simple, (dense or lax).
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 (greenish) oblong, 2.5–3.5 × 1.2–1.5 mm, lateral pair saccate basally, (glabrous);
petals white, oblanceolate to spatulate, (5–)6–8 × 2–4 mm, apex rounded;
filaments 2.5–4 mm;
anthers oblong, 0.6–1 mm.
erect to erect-ascending, 7–16 mm, (glabrous).
ascending to divaricate, (2–)5–20(–30) mm, (glabrous).
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.
ascending to suberect, (not appressed to rachis), slightly torulose, sometimes slightly curved, (0.7–)1–2.5(–2.8) cm × 0.8–1.2(–1.5) mm;
valves each with distinct midvein extending full length;
ovules 10–24 per ovary;
style 0.5–1.2(–2) mm, (slender).
narrowly winged throughout, oblong, 0.9–1.9 × 0.5–0.7 mm;
wing to 0.1 mm wide distally.
not winged, broadly ovate, 0.6–1.2(–1.5) × 0.5–1 mm.
= 32.
Arabis georgiana
Arabis nuttallii
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 nuttallii, the second most widespread native North American species of the genus, is variable in density of indumentum, types of trichomes, plant height, pedicel length, fruit width, leaf shape, flowering and fruiting time, and elevation. As indicated by R. C. Rollins (1941, 1993), the variation seems to be sporadic and does not correlate with clear-cut entities and, therefore, the species cannot be subdivided meaningfully.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
WildflowerSearch
iNaturalist
USDA Plants Database
BC
WA
Flora NW
PNW Herbaria
