Hairy Whitetop

Lepidium appelianum

Hairy Whitetop

Family: Brassicaceae

Other Scientific Names:

Cardaria pubescens

Other Common Names: globepodded hoarycress
Weed class: C
Year Listed: 1988
Native to: Central Asia, Himalayas and Western Pakistan
Is this Weed Toxic?:

not known to be

Why Is It a Noxious Weed?

Hairy whitetop has the potential to reduce the value of high-priced wheat lands in areas.

How would I identify it?

General Description

Hairy whitetop is a perennial plant with a spreading root system from which many aerial shoots are produced.

Flower Description

Flower clusters in somewhat flat-topped racemes made up of 20-30 flowers. Flowers on slender pedicles, each with 4 sepals, 4 white petals and 6 stamens.

Leaf description

Leaves are alternately arranged, pubescent and up to about 4 inches long. Leaf margins are irregularly toothed (dentate). Lower leaves have stalks (petioles), upper leaves do not have stalks and have lobed, clasping bases.

Stem description

Stems are stout, pubescent, spreading to upright and 4 to 20 inches tall.

Fruit Seed Description

Seed pods (silicles) are inflated, globular to ellipsoidal in shape and covered with fine hairs. Pods are 0.12 to 0.20 inches (3-5mm) long by 0.16 to 0.24 inches (4-6mm) wide.

May Be Confused With

Hoary cress, Cardaria draba, is similar but does not have hairs on the seed pods (silicles).

Where does it grow?

Hairy whitetop grows well on a variety of soils in dry and moist areas, though shows a preference for alkaline soils. It grows in open conditions in pastures and disturbed areas. Please click here to see a county level distribution map of hairy whitetop in Washington.

How Does it Reproduce?

Hairy white is self-incompatible and is pollinated by insects. Plants spread by seed which each producing around 300-2,000 per plant. Shoots develop from buds which can form on any part of the permanent root system.

How Do I Control It?

Cultural Control

Alfalfa is a more effective competitor than perennial grasses where moisture is abundant.

Herbicide Control

Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.

For More Information

See our Written Findings for more information about hairy whitetop (Cardaria pubescens).

Report on hairy whitetop from the book "Weed Control in Natural Areas in the Western United States"

Images from the UW Herbarium (WTU) image database of whitetop, Lepidium appelianum

Additional Photos