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Parrot's Feather

A popular aquatic garden plant that spreads with water currents, animals, boats/trailers and fishing gear. Dense stands can stagnate water, and increase breeding grounds for mosquitoes learn more »

Zebra/Quagga Mussels

These tiny freshwater mussels clog drains, damage infrastructure, and are very costly to control/eradicate learn more »

Giant Hogweed

A towering toxic invasive plant with WorkSafe BC regulations learn more »

European Fire Ant

A tiny ant with a toxic sting learn more »

Purple Loosestrife

An aggressive wetland invader that threatens plant and animal diversity learn more »

Orange Hawkweed

Also yellow, these invasive plants replace native vegetation along roadsides, and threaten areas not yet reforested learn more »

Japanese Knotweed

Grows aggressively through concrete, impacting roads and house foundations learn more »

Spotted Knapweed

A single plant spreads rapidly with up to 140,000 seeds per square metre learn more »

Scotch Broom

An evergreen shrub that invades rangelands, replaces forage plants, causes allergies in people, and is a serious competitor to conifer seedlings learn more »

Hoary Cress

Species
Cardaria draba

Hoary cress (Cardaria draba) is a perennial plant that invades hay fields, rangeland meadows and along roadsides, competing with native vegetation. It can be found on open, unshaded areas at low- to mid-elevations on the coast, and interior grassland and forest regions of BC. It spreads primarily by roots and seed dispersal; each plant can produce up to 4800 seeds. Plants grows to 0.6 m high. One plant can spread up to 3.5m2 in one year with no competition nearby.

Considered regionally noxious under the BC Weed Control Act, hoary cress was most likely brought to North America in contaminated alfalfa seeds during the 1800s, and can still spread the same way. Also known as "white-top," hoary cress has white flowers with four petals, giving it a flat-topped appearance. Arrowhead-shaped leaves adorn the stem and are covered with soft white hairs, giving the foliage a grey-green appearance.

Hoary cress is a concern in the agricultural regions of the Okanagan and Thompson, and present in the Kootenays and Cariboo, but less frequent in southern BC.  

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Gallery: Hoary Cress