Sibara virginica (L.) Rollins
Family: Brassicaceae
Virginia winged rockcress,  more...
[Arabis virginica (L.) Poir.,  more]
Sibara virginica image
John Hilty  
Herb with a taproot 10 - 40 cm tall Stem: stiff, ascending or decumbent, usually branched near the base, reddish in strong sun, hairy below, less hairy to hairless above. Flowers: in dense, branched clusters (racemes), which are borne terminally and axillary on the stems. Flower stalks 1 - 3 mm long. Sepals four, distinct, upright, whitish green to purplish in strong sun, to 2 mm long, to 1 mm wide, oblong- lance-shaped, tips slightly pointed to rounded. Petals four, distinct, white or pinkish, 2 - 3 mm long, to 1 mm wide, tips rounded. Stamens six, upright. Anthers yellow. Fruit: a long, narrow pod (silique), ascending, to 2 cm long, to 2 mm wide, slightly compressed, two-valved, with a short beak, on stalks to 4 mm long. Basal leaves: deeply pinnately divided, 4 - 8 cm long, oblong. Segments divergent, oblong. Stem leaves: alternate, pinnately divided (or uppermost lance-linear), to 4 cm long, to 1 cm wide, hairy on leafstalks and leaf axes. Leaf segments five to fourteen on each side of axis, reduced basally, awl- to lance-shaped, tips pointed, typically non-toothed or with a small basal lobe, sometimes with one or two hairs near the tips. The leaves overwinter as a basal rosette.

Similar species: No information at this time.

Flowering: mid-April to late May

Habitat and ecology: Introduced from farther south. This spring ephemeral weed of sandy nursery plots can be found in the southern sector of the Chicago Region. It is also occasional in sandy cornfields, but disappears by the third week of June. Also look for it in disturbed areas, waste ground, and along roads and railroads.

Occurence in the Chicago region: non-native

Etymology: Virginica means "of or from Virginia."

Author: The Morton Arboretum

Resembling Cardamine parviflora in aspect; stiff, ascending or decumbent, 1-4 dm, often branched from the usually hirsute base, the hairs simple or bifurcate; basal lvs oblong, 4-8 cm, deeply pinnatifid or lyrate-pinnatifid into oblong divergent segments; cauline lvs similarly pinnatifid, or the uppermost lance-linear and entire; racemes compact; pet 2-3 mm, white or pinkish; frs ascending (often more strongly so than the short pedicels), 1.5-2.5 cm נ1.5-2 mm, scarcely beaked; seeds suborbicular, narrowly winged, 1.2-1.5 mm wide; 2n=16. Woods, fields, and roadsides; Va. to Ind. and Kans., s. to Fla. and Tex. Mar.-May. (Arabis v.)

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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