Lepidium draba

{{Speciesbox

|name = Whitetop

|image = Cardaria_draba1.jpg

|genus = Lepidium

|species = draba

|authority = L.

|subdivision_ranks = Subspecies

|subdivision =

Lepidium draba subsp. draba (= Cardaria draba)
Lepidium draba subsp. chalepense (L.) P.Fourn. (=Cardaria chalepensis)

|synonyms = Cardaria draba (L.) Desv.

}}

Lepidium draba, also known as whitetop, hoary cress,{{BSBI 2007 |accessdate=2014-10-17 }} or Thanet cress,{{cite web|url=https://www.gardenorganic.org.uk/sites/www.gardenorganic.org.uk/files/organic-weeds/cardaria-draba.pdf|title=The biology and non-chemical control of Hoary Cress (Cardaria draba (L.) Desv.)|author1=W Bond|author2=G Davies|author3=R Turner|website=Gardenorganic.org.uk|access-date=22 March 2022}} is a rhizomatous perennial flowering plant in the family Brassicaceae. It is native to western Asia and southeastern Europe and has been widely introduced elsewhere.

Description

File:Cardaria draba vesnovka obecná 1.jpg

Whitetop is a perennial herb that reproduces by seeds and by horizontal creeping roots.{{Cite web |title=Lepidium draba Profile – California Invasive Plant Council |url=https://www.cal-ipc.org/plants/profile/cardaria-draba-profile/ |access-date=2023-06-17 |language=en-US}} The stem is stoutish, erect or spreading, 10 to 80 cm tall, branched, covered sparsely with ash-colored soft hairs to heavily covered. The leaves are alternating, simple, and mostly toothed. The basal leaves are 4 to 10 cm, have a slight stem (petiole), and are long and flat, lance-shaped to egg-shaped, with the narrow end attached to the stalk.{{Cite journal |last=Scurfield |first=G. |date=July 1962 |title=Cardaria Draba (L.) Desv. |url=http://dx.doi.org/10.2307/2257459 |journal=The Journal of Ecology |volume=50 |issue=2 |pages=489–499 |doi=10.2307/2257459 |jstor=2257459 |issn=0022-0477|url-access=subscription }} On the upper part of the stem the leaves are attached directly to the stalk (sessile), are 2 to 6.5 cm long, and are oblong or tapering the point, with broad bases that clasp the stalk.{{Cite web |title=Hoary cress (Cardaria draba) |url=https://agri.nv.gov/Plant/Noxious_Weeds/WeedList/Hoary_cress_(Cardaria_draba)/ |access-date=2023-06-17 |website=agri.nv.gov}} Whitetop has slightly domed flower clusters in which the individual flower stalks grow upward from various points off the branch to approximately the same height (corymb-like). The petals are white, clawed, and 3 to 5 mm long, about twice the length of the sepals. Typically, each flower has four petals.{{Cite journal |last1=MULLIGAN |first1=GERALD A. |last2=FINDLAY |first2=JUDY N. |date=January 1974 |title=The biology of canadian weeds. 3. cardaria draba, c. chalepensis, and c. pubescens |journal=Canadian Journal of Plant Science |volume=54 |issue=1 |pages=149–160 |doi=10.4141/cjps74-024 |issn=0008-4220|doi-access=free }}

File:Heart-podded Hoary Cress.jpg

Uses

Hoary cress was traditionally used for medicinal purposes, including anti-inflammatory and antibacterial treatments.

Distribution

It is native to western Asia and southeastern Europe and is an invasive species in North America, introduced by contaminated seeds in the early 1900s. Also known as Cardaria draba, hoary cress is a weed in much of south-east and south-west Australia as well.{{cite web|title=Hoary Cress|url=http://www.weeds.org.au/cgi-bin/weedident.cgi?tpl=plant.tpl&state=&s=®ion=all&card=H27|website=Weed Identification & Information|publisher=Australian Weeds Committee|accessdate=2015-04-12|archive-url=https://web.archive.org/web/20150414090619/http://www.weeds.org.au/cgi-bin/weedident.cgi?tpl=plant.tpl&state=&s=®ion=all&card=H27|archive-date=2015-04-14|url-status=dead}}{{cite web|title=Weedy Connection: Hoary Cress|url=https://www.weedyconnection.com/database/hoary_cress.html|accessdate=2023-06-14}} It has been suggested that native grasses from the Poa genera may be able to outcompete hoary cress in North America.{{Cite journal |last1=Puliafico |first1=Kenneth P. |last2=Schwarzländer |first2=Mark |last3=Price |first3=William J. |last4=Harmon |first4=Bradley L. |last5=Hinz |first5=Hariet L. |date=March 2011 |title=Native and Exotic Grass Competition with Invasive Hoary Cress (Cardaria draba) |url=https://www.cambridge.org/core/journals/invasive-plant-science-and-management/article/abs/native-and-exotic-grass-competition-with-invasive-hoary-cress-cardaria-draba/A4D6E9CABA2E1BEB835BFFEC1FB69EE3#access-block |journal=Invasive Plant Science and Management |language=en |volume=4 |issue=1 |pages=38–49 |doi=10.1614/IPSM-D-10-00041.1 |s2cid=85677227 |issn=1939-7291|url-access=subscription }}

=Distribution in United States=

Image:Cardaria-draba-distribution-USDA.png

References

External links

[https://www.invasivespeciesinfo.gov/profile/whitetop Species Profile - Whitetop (Lepidium draba)], National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for Whitetop.
[https://www.invasiveplantatlas.org/subject.html?sub=5232 Hoary cress - Lepidium draba], Invasive Plant Atlas of the United States,
[https://wiki.bugwood.org/Cardaria_spp., Cardaria_spp], Bugwood Wiki - Invasive Pest Management