DistributionRead full entry
Hoary cress is native to southwestern Asia and has been introduced to every continent except Antarctica . There is evidence that all 3 species were introduced to many locations in North America as contaminants in alfalfa (Medicago sativa) seed from Turkestan in the early 1900s up until around 1922 [35,67]. Turkestan alfalfa and its associated weeds are more common in the West because this type of alfalfa did not grow well in the more humid regions of the east . Plants database provides a distributional map of hoary cress and the 3 individual species.
Lens-podded hoary cress is native to Kazakhstan, Uzbekistan, and Turkmenistan, and also occurs (but is likely not native) in Pakistan, northern India, Afghanistan, Iran, Iraq, Syria, and Israel. It has been introduced to England, Argentina, and North America. Lens-podded hoary cress was 1st collected in the U.S. in California, in 1918 and in Alberta, Canada, in 1926 . It is a common field weed in central and western Canada and the U.S., but is rare in eastern North America [67,98]. Lens-podded hoary cress is most invasive of the 3 hoary cress species in Canada, particularly in irrigated areas of Saskatchewan, Alberta, and British Columbia .
The 1900s was not the earliest introduction of heart-podded hoary cress to North America. It was probably initially introduced by early American settlers from Europe, possibly as an ornamental or garden plant. It was collected in 1862 on Long Island, New York, and in 1878 in Ontario . It was likely introduced multiple times and from other places since then . Heart-podded hoary cress is native to the Balkan Peninsula, Georgia, Armenia, Azerbaijan, Turkmenistan, Kazakhstan, southern Russia, Turkey, Israel, Syria, Iraq, and Iran. Heart-podded hoary cress is the least abundant of the hoary cresses in Canada, where it occurs primarily in southern Manitoba and southern Alberta . It occurs throughout the U.S. except in southern portions of California (Mojave and Colorado deserts) and the south-central states [20,60]. It appears to be most invasive in big sagebrush (Artemisia tridentata) ecosystems in eastern Oregon, where it occupies >100,000 ha ( and references therein).
Globe-podded hoary cress is native to Kazakhstan, Uzbekistan, Turkmenistan, northern Iran, and Afghanistan, and can be found in Argentina and North America. It is a common weed in central and western Canada and the U. S., but is rare in eastern North America. It was 1st collected in the U.S. in Michigan in 1919, and in Alberta, Canada in 1926 . Globe-podded hoary cress occurs in the same areas as lens-podded hoary cress and is frequently associated with it in Canada and the U.S. .
Hoary cress is primarily a weed of agricultural lands and disturbed sites such as roadsides and railways. Reports of its occurrence in wildlands or rangelands are rare. The following biogeographic classification systems are presented to demonstrate where hoary cress might be present or invasive, based on reported occurrence and biological tolerance to factors likely to limit its distribution. Precise distribution information is unavailable. Therefore, these lists are speculative and not exhaustive, and hoary cress may be present and possibly invasive in other vegetation types.