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Cardaria draba   (L. ) Desv.
Riley County, Kansas
Height: 4-24 inches
Family: Brassicaceae - Mustard Family
Flowering Period:   April, May, June, July
Also Called: Whitetop.
Stems: Erect, stout, branching above, short-hairy below, nearly smooth above.
Leaves: Alternate, simple, bluish-green, oblong to egg-shaped, ascending or erect; margins irregularly toothed, wavy or entire; basal leaves stalked, 1.6 to 4 inches long, to 1.6 inches wide; upper leaves clasping, oblong to lanceolate, .8 to 2.8 inches long.
Inflorescences: Racemes, numerous, densely-flowered, terminal; form broad, flat-topped corymbs.
Flowers: Stalk 2/5 to 3/5 inch long; sepals 4, blunt, glabrous, 1/12 to 1/10 inch long; petals 4, spatulate, 1/8 to 1/6 inch long, white to cream, clawed; margins toothed to entire; nectar glands large, well-developed; stamens 6.
Fruits: Pod, broadly heart-shaped, 1/10 to 1/8 inch long, 1/8 to 1/5 inch wide, somewhat flattened, glabrous; stalks 2/5 to 3/5 inch long, seeds 2-4, oval, about 1/12 inch wide, reddish-brown.
Habitat: Roadsides, open waste areas, cultivated fields; disturbed, alkaline soils.
Distribution: East 3/4 of Kansas.
Origin: Native to Eurasia; introduced.
Forage Value: Livestock will graze it when other forage is unavailable but it will irritate the mucous membranes.
Uses: Small mammals and ground-foraging birds eat the seeds.
Comments: An aggressive weed that forms large stands. It is difficult to eradicate and is a serious problem in the western U.S.

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Hoary cress inflorescence
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Riley County, Kansas
Hoary cress inflorescence
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Hoary cress pods
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Hoary cress leaves
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Riley County, Kansas