Arabidopsis lyrata

This record is consistent with the treatment of Arabidopsis lyrata sensu FNA (2010, vol. 7) which includes ssp. kamchatica and ssp. petraea. According to FNA, "The occurrence of subsp. petraea in North America was pointed out by S. L. O’Kane and I. A. Al-Shehbaz (1997) and Al-Shehbaz and O’Kane (www.aspb.org/publications/arabidopsis, 2002); no specimens were cited. G. A. Mulligan (1996), who treated the taxon as Arabis media, did not cite specimens either. Representative Alaskan collections were examined, including Parker 7995 (MO) and Hardy 134 (CAS, MO)."

The concept of the species for which the record was created was for the broad sense of Arabis lyrata, accepted by Kartesz (1994 checklist), which includes Arabis kamchatica as a variety, with the occurrence of ssp. petraea in the U.S. not yet known, but likely to have been included in that concept. Mulligan (1995 synopsis, Rhodora 97: 109-163) and Kartesz (1999) treat A. lyrata more strictly, excluding A. kamchatica and A. media (= Arabidopsis lyrata ssp. petraea) as distinct species.

Arabidopsis lyrata is a perennial or biennial forb occurring in a variety of habitat types (including forests, streambanks, slopes, tundra, serpentine barrens, outcrops, cliffs, ledges, and sand dunes) worldwide. In North America, this species is found from Alaska north through the Northwest Territories, east through Ontario and Massachusetts, south to North Carolina, and Tennessee, north to Minnesota, and in Washington in the United States and Canada, and it occurred historically in Georgia, Mississippi, and Montana. There are over 1,500 estimated occurrences of this taxon, which are potentially threatened by development, rights-of-way maintenance, invasive species, and other threats in some places. Little is known about threats or trends, but with a large range extent, high number of occurrences, abundant habitat, broad habitat preferences, and no obvious intrinsic vulnerabilities, Arabidopsis lyrata is considered secure.

Arabidopsis lyrata occurs worldwide in North America, Europe, and Asia (POWO 2025). In North America, this species is found from Alaska north through the Northwest Territories, east through Ontario and Massachusetts, south to North Carolina, and Tennessee, north to Minnesota, and in Washington in the United States and Canada (FNA 2010). It is considered historical in Georgia, Mississippi, and Montana (MNHP 2025, Weakley and the Southeastern Flora Team 2025). Range extent was estimated using herbarium specimens and photo-based observations documented between 1994 and 2025 (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025). See individual entries for distribution details about the three subspecies.

By applying a 1 km separation distance to herbarium records and photo-based observations documented between 1994 and 2025, there are estimated to be over 1,500 occurrences rangewide (GBIF 2025, iNaturalist 2025, RARECAT 2025, SEINet 2025).

Although threats are not widely documented, Arabidopsis lyrata is potentially threatened by development, rights-of-way maintenance, invasive species, and other threats in some places. However, their overall impact is likely negligible given the species' broad range, large number of occurrences, tolerance of light disturbance, and affinity for typically abundant habitats, as well as no obvious intrinsic vulnerabilities.