Hairy Whitetop
Lepidium appelianum
Washington State Classification
Class C — Widespread, County-Selected Control
Hairy whitetop has the potential to reduce the value of high-priced wheat lands in areas.
Quick Reference
Identification
Growth Habit
Hairy whitetop is a perennial plant with a spreading root system from which many aerial shoots are produced.
Leaves
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.
Flowers
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.
Fruit & Seeds
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.
Impact
Hairy whitetop has the potential to reduce the value of high-priced wheat lands in areas.
Ecology & Spread
Habitat
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.
Spread Mechanisms
Reproduction
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.
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