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Calepina irregularis (Asso) Thell.
Family: Brassicaceae
Calepina irregularis image
Stems several from base, (1-)2-8 dm, unbranched or branched distally. Basal leaves early rosulate; petiole (0.2-)1-3.5(-6) cm; blade obovate, spatulate, or oblanceolate, (0.8-)2-5(-9) cm × (3-)10-30 mm, base attenuate. Cauline leaves: blade oblong to lanceolate, (1-)2-7(-8) cm × (4-)10-20(-30) mm, base sagittate or amplexicaul, apex obtuse to acute. Racemes with straight rachis. Fruiting pedicels straight or curved upward, (3-)5-10(-13) mm. Flowers: sepals oblong or ovate, 1.2-2 × 0.5-1 mm; petals (1.5-)2-3 × 0.5-1.5 mm, unequal, abaxial pair larger than adaxial (longer than sepals); filaments 1-1.5 mm; anthers ca. 0.3 mm; gynophore 0.1-0.2 mm. Fruits 2.5-3.5(-4) × 2-3 mm, abruptly tapering to a conical, beaklike apex, 0.5-0.8 mm. Seeds brown, 1.3-1.6 mm. 2n = 14, 28. Flowering Mar-May. Fields, waste places, roadsides; 0-200 m; introduced; Md., N.C., Va.; Europe; c, sw Asia; n Africa. The fruits of Calepina irregularis and Neslia apiculata are remarkably similar; the two can easily be separated by the presence of white instead of yellow petals and by the absence of indumentum in Calepina.

A glabrous European annual or biennial with a lax raceme, unequal pet, and rugose frs, is casually intr. in Va. and N.C. The cauline lvs are clasping, with acute, patent auricles.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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