Whitetop (Lepidium draba L.)
Also known as hoary cress, Thanet cress, heart-podded pepperweed; also classified as Cardaria draba (L.) Desv.
↑Summary
A rhizomatous perennial invasive in much of North America, especially in the West.
↑Range - Expand
| Legend | Color |
| Introduced | |
| Introduced or Not Present |
This tentative map is based on our own research. It may have limited data on Canada and/or Mexico, and there is some subjectivity in our assignment of plants as introduced vs. expanded. Read more in this blog post.
Although this plant occurs somewhere in each of these regions, it may only occur in a small part of some or all of them.
↑Habitat
Found on disturbed sites. In arid regions of North America, this species is mostly restricted to locally-moist habitats including riparian areas, marshes, roadside ditches, and irrigated cropland. In more humid regions, it ventures into more mesic habitats including fields, meadows, roadsides, and gardens, but it is usually less common.
More common and generally more invasive in the West; absent from the southeast, and populations in the northeast are scattered and it is rare in much of this range. As this species often spreads through agriculture and thrives in anthropogenic habitats, it has major gaps in its range in North America that may reflect differences in land use and history of establishment more than inherent constraints of climate and soil type. It likely can survive
Prefers alkaline or high pH soils, which may explain its absence in the southeast, but otherwise able to survive in a wide range of conditions.
↑Life Cycle
Whitetop is a rhizomatous perennial that spreads both vegetatively and by seed.
↑Links & External Resources
• Cardaria draba (whitetop) | USDA PLANTS Database (About This Site)
• Lepidium draba | Biota of North America Project (BONAP) (About This Site)
• Lepidium draba | Flora of North America (About This Site)
• Lepidium draba | Missouri Plants (About This Site)
• Hoarycress | Maryland Biodiversity Project (About This Site)
• Lepidium draba (White-top) | Minnesota Wildflowers (About This Site)
• Lepidium draba L. (Hoary Cress) | Digital Atlas of the Virginia Flora (About This Site)
