[The Genus Cardaria East of the Cascade Mountains of Oregon and Washington]

Heart-podded Hoarycress, Hoary Cress, Hoary Pepperwort, White Top

Cardaria draba

Synonyms: Cardaria draba ssp. draba, Lepidium draba, Lepidium draba ssp. draba

Heart-podded Hoarycress, Hoary Cress, Hoary Pepperwort, White Top: Cardaria draba (Synonyms: Cardaria draba ssp. draba, Lepidium draba, Lepidium draba ssp. draba)

Hoary cress as seen along Rock Creek at the Escure Ranch, eastern Adams County, Washington................May 14, 2011.

Characteristics:

Hoary cress is also known as heart-podded hoary cress. It is a fairly common, weedy perennial of the west. Its erect or spreading stems reach from 20-50 cm tall from strongly spreading rhizomes. The herbage is minutely hairy, giving it a gray-green appearance. The ovate-oblong to oblong-oblanceolate leaves are toothed, and range from 4-10 cm in length. The lower leaves are petiolate, while the upper ones are sessile and clasping. The leaves are alternate on the stems.

The inflorescence is more or less corymbose, with numerous racemes. The result is that the inflorescence appears flat-topped. The 4 sepals are about 2-2.5 mm long, while the 4 white petals are 3-4 mm long. 6 stamens are present as well as 1 style. The seed capsules are inflated silicles, which are deltoid-ovoid or cordate-ovoid in shape.

New plants arise from seeds as well as segments of roots. Once established, this species is hard to eradicate.


Habitat:

Hoary cress is found in old fields, along roadsides, and in other open, disturbed places.


Range:

A European weed, hoary cress is found throughout much of the lowlands of the western United States.


Inflorescence of Heart-podded Hoarycress, Hoary Cress, Hoary Pepperwort, White Top: Cardaria draba (Synonyms: Cardaria draba ssp. draba, Lepidium draba, Lepidium draba ssp. draba)

A close-up of the inflorescence of hoary cress as seen along Rock Creek at the Escure Ranch, eastern Adams County, Washington................May 14, 2011.

Heart-podded Hoarycress, Hoary Cress, Hoary Pepperwort, Whitetop, White Top: Cardaria draba (Synonyms: Cardaria draba ssp. draba, Cardaria draba var. draba, Lepidium draba, Lepidium draba ssp. draba) - Inflorescence of Heart-podded Hoarycress, Hoary Cress, Hoary Pepperwort, Whitetop, White Top: Cardaria draba (Synonyms: Cardaria draba ssp. draba, Cardaria draba var. draba, Lepidium draba, Lepidium draba ssp. draba)

Additional views of hoary cress as seen along Oregon Highway 19 along the John Day River in western Grant County, Oregon..............June 2, 2011.

Heart-podded Hoarycress, Hoary Cress, Hoary Pepperwort, Whitetop, White Top: Cardaria draba (Synonyms: Cardaria draba ssp. draba, Cardaria draba var. draba, Lepidium draba, Lepidium draba ssp. draba) - Heart-podded Hoarycress, Hoary Cress, Hoary Pepperwort, Whitetop, White Top: Cardaria draba (Synonyms: Cardaria draba ssp. draba, Cardaria draba var. draba, Lepidium draba, Lepidium draba ssp. draba)

What appears to be hoary cress as seen in a weedy swale near the Whitehorse Ranch Road east of the Pueblo Mountains of southeastern Oregon.............June 1, 2012.

Paul Slichter