2. Arabis caucasica Willdenow, Enum. Pl., Suppl. 45. 1814.
Perennials; (stoloniferous, with vegetative rosettes, loosely cespitose to somewhat pulvi-nate); sparsely to moderately pubescent, trichomes stalked, cruciform, stellate, mixed with simple and forked-stalked ones. Stems several to many from base, erect, ascending to decumbent, branched (several), 1.5-3.5(-5) dm. Basal leaves: petiole 0-1 cm; blade spatulate, oblanceolate, oblong, or obovate, 2-5.5(-8) cm × 9-18(-25) mm, margins dentate to denticulate, apex obtuse or acute, surfaces usually pubescent, rarely subglabrate, trichomes stellate with some rays branched. Cauline leaves 4-8; blade oblong or ovate, 1-5 cm × 5-20 mm, base subcordate or auriculate, margins usually dentate, rarely subentire, apex acute or obtuse. Racemes simple, (lax). Fruiting pedicels ascending to divaricate, 7-17(-20) mm. Flowers: sepals oblong, 4.5-8 × 1-2 mm, lateral pair conspicuously saccate basally; petals white, spatulate to obovate, 10-19 × 4-8 mm, apex obtuse; filaments 4-7 mm; anthers oblong, 0.7-1.2 mm. Fruits ascending to spreading, torulose, (3-)4-7 cm × 1-2 mm; valves each with midvein absent or obscure, along proximal 1/2; ovules 40-60 per ovary; style 0.5-1 mm. Seeds narrowly winged throughout, ovate, 1-1.4 × 0.9-1.1 mm; wing 0.1-0.2 mm wide. 2n = 16.
Flowering Jun-Aug. Rare garden escape; introduced; B.C., N.B., Ont., Que., Yukon; Mich., N.Y.; sw Asia.