Hoary Cress Information
(Cardaria draba)
Hardy perennial with stout, erect or procumbent stems
Seedling leaves have a sharp pepper taste
Cardaria draba is distinguished from other Cardaria species by:
*Heart-shaped fruit containing only 2 seeds
*As fruit matures and dries, distinct veins appear
Cardaria draba is distinguished from Lepidium species by:
*Lepidium leaves are perfoliate (completely encircle the stem)
*Lepidium fruit is flattened, keeled or winged
*Lepidium fruit is dehiscent, cardaria is indehiscent
Habitat:
*Prefers non-shaded, moist, disturbed soils with little competition
*Roadsides and ditches
*Cropland and wasteland
*Watercourses and irrigation canals
*Gardens
*Feedlots
Flowers:
*Monoecious
*Blooms May through July
*Flowers are four-petalled with long, narrow bases (spoon-shaped)
Seeds:
*Two seed per fruit
*Plants and produce up to 850 fruits per flowering stem
*Germination rates of 93% are common
*Temperature range for germination: 68-86 degrees
*Dispersal by animals, humans and water
Roots:
*Roots grow 3-6 feet deep
*25 day old plant: 10" taproot, 5-6 lateral roots
*100 day old plant: 48 shoots, 80 root buds
*1/2" root segment can regrow if within 2-4" of surface
Growth and reproduction:
*Under ideal conditions, rosettes form 2-3 weeks after emergence, roots develop within 5 weeks
and aboveground branching within 13 weeks
*Lateral root growth can exceed 10 feet during the first year, 2-3 in the following seasons
*Reproduction from rootstocks and seeds
Management:
*Mowing 2-3 ties per season after flowering, can weaken the plant
*Repeated cultivation at 10 day intervals prior to seed set Herbicides: chlorsulfuron, metsulfuron,
2, 4-D
Threats:
*Reduces crop yields and forage production, toxic to livestock
*Displaces native species reducing biodiversity