Coronopus is a genus name historically applied within the cabbage and mustard family, Brassicaceae (order Brassicales), to a small group of low, spreading annual herbs commonly known as swinecress or wartcress. Plants placed here have many long, often prostrate stems, deeply lobed leaves, and small white flowers, and give off a strong scent — reminiscent of garden cress (Lepidium sativum) — when the foliage is crushed.
Taxonomically, Coronopus is best understood today as a name in transition rather than a stable, independent genus. The GBIF Backbone Taxonomy formally accepts the genus (authorship L., i.e. Linnaeus) under Brassicaceae, but its own backbone data show almost nothing left under it: the type-adjacent species once housed here, such as Coronopus didymus, are resolved by GBIF's name-matching service as synonyms of species now placed in Lepidium (Coronopus didymus → Lepidium didymum). Wikipedia's treatment agrees, describing Coronopus outright as "a synonym for the accepted genus name Lepidium." At the same time, a number of other checklist datasets aggregated by GBIF still list Coronopus as a small, independently accepted genus of two or three species, so usage is not fully settled across sources — some literature and regional floras continue to use Coronopus for these plants, especially in older or non-monographic treatments.
The two species most associated with the name are Lepidium didymum (lesser swine-cress), thought to be native to South America, and Lepidium squamatus — itself reclassified from Coronopus squamatus around 2004 and briefly also known as Lepidium coronopus — thought to be native to the Mediterranean. Both have become widespread, weedy, introduced plants well outside their native ranges, growing as common weeds of disturbed and cultivated ground.
Distribution
Coronopus-type plants comprise Lepidium didymum (lesser swine-cress), likely native to South America, and Lepidium squamatus, likely native to the Mediterranean region. Both have become widespread as introduced, weedy plants far outside their native ranges.
Taxonomy Notes
Coronopus L. is now widely treated as a synonym of Lepidium: GBIF's backbone resolves its best-known member, Coronopus didymus, as a synonym of Lepidium didymum, and Wikipedia describes Coronopus outright as "a synonym for the accepted genus name Lepidium." However, taxonomic treatment is not fully uniform — some checklist datasets aggregated by GBIF still carry Coronopus as a small, independently accepted genus of Brassicaceae with two or three species, and older or regional floras may continue to use the name. GBIF's own backbone record for the accepted genus Coronopus lists only one descendant, Coronopus australis, which is itself flagged as taxonomically "doubtful."
