Southwest Desert Flora

After recent phylogenetic studies the Scrophulariaceae is reduced to a medium sized family containing about 76 genera and approximately 1,575 species. Former members were moved to other families including Plantaginaceae and Orobanchaceae, while others were placed in new families.

The United Stated Department of Agriculture (USDA) uses the traditional classification and thus in North America there are approximately 95 genera and about 1,228 species. Some of the largest genera in North America are Penstemon (250 species), Mimulus (91 species), Castilleja (109 species) and Pedicularis (36 species) and Veronica (34 species). Of note is the type genus Scrophularia, which also grows in North America, has been removed from the new classification.

Species in the Scrophulariaceae, Figwort or Snapdragon family are usually annual and perennial herb/forbs, rarely small shrubs. They are distributed world-wide with greatest diversity in the temperate areas (Mediterranean) including tropical mountains.

Common characteristics include: Plants: Partial root parasites; a few wholly parasitic; Castilleja, Pedicularis, Cordylanthus; Leaves: opposite, alternate or rarely whorled, simple, entire, pinnately dissected; without stipules Inflorescence: raceme or cyme; Flowers: sepals 5 or 4 lobes united, petals 5 or 4 fused lobes (sympetalous), tube-like, some 2-lipped (bilabiate) bisexual, zygomorphic or rarely actinomorphic; Fruit: 2-chambered capsule or berry.

There are few species of economic importance other than Digitalis (Foxgloves) which contains digitalin which is used in the treatment of heart conditions. Some species are popular as garden ornamentals including Penstemon, Antirrhinum (Snapdragons) and a few others have economic value for their naturally beautiful flowers and vegetatively handsome plants.

Arizona is well represented with species of Castilleja, Mimulus, Penstemon and Veronica.