Arida is a genus of flowering plants in the daisy family (Asteraceae), native to the arid and semi-arid regions of the southwestern and south-central United States and northern Mexico. The genus was described by D.R. Morgan and R.L. Hartman and published in Sida 20: 1410 (2003), with the authorship traced to (R.L.Hartm.) D.R.Morgan & R.L.Hartm. It belongs to the order Asterales, class Magnoliopsida, within the vascular plant phylum Tracheophyta.
The genus comprises small shrubs and perennial herbs adapted to dry, desert, and grassland habitats typical of the Chihuahuan Desert and surrounding regions. Species in Arida bear the characteristic composite flower heads of the Asteraceae family. The genus includes approximately six species, among them Arida arizonica, Arida blepharophylla, Arida carnosa, Arida mattturneri, Arida parviflora, and Arida riparia.
Taxonomically, Arida is treated by some authorities as a synonym of Leucosyris Greene, and the English Wikipedia article for "Arida (plant)" redirects to the Leucosyris entry. The GBIF backbone similarly treats Arida as a synonym of Leucosyris, though regional checklist datasets continue to recognize Arida as an accepted genus. This reflects an ongoing taxonomic debate around the circumscription of genera within the Astereae tribe of Asteraceae.
Etymology
The genus name Arida derives from the Latin aridus, meaning "dry" or "parched," reflecting the xeric habitats — desert scrub, dry grasslands, and rocky slopes — in which these plants grow. Authorship is attributed to (R.L.Hartm.) D.R.Morgan & R.L.Hartm., published in 2003.
Distribution
Arida is native to the southwestern and south-central United States and northern Mexico, with species occurring primarily in arid and semi-arid environments including Chihuahuan Desert scrub and desert grasslands.
Taxonomy Notes
Arida (R.L.Hartm.) D.R.Morgan & R.L.Hartm. (published in Sida 20: 1410, 2003) is treated by the GBIF backbone and English Wikipedia as a synonym of Leucosyris Greene (Asteraceae, tribe Astereae). Some regional checklists continue to recognize Arida as an accepted genus with approximately six species. The circumscription of this group remains unsettled among taxonomic authorities.
