Barkleyanthus is a monotypic genus[1] of flowering plants in the aster family, Asteraceae, containing the single species Barkleyanthus salicifolius, a plant formerly classified in the genus Senecio.[2] [3] It is native to North and Central America, where its distribution extends from the southwestern United States to El Salvador. Its common names include willow ragwort,[3] willow groundsel, Barkley's-ragwort,[4] and jarilla.[1]
This plant is a shrub producing a branching stem usually about one to two meters tall, but known to exceed 4 meters at times. The leaves are roughly lance-shaped and are alternately arranged, sometimes more densely toward the ends of branches. They are up to 10 or 15 centimeters long. The inflorescence is often a wide array of several flower heads, but they may also be clustered in the leaf axils or branch tips. The head contains a few yellow ray florets, which are pistillate, and up to 25 or more yellow disc florets, which are bisexual. The fruit is a rough-textured, pyramidal or prism-shaped cypsela up to a centimeter long including its pappus of many barbed white bristles.[2]
This plant is abundant in parts of its range, particularly in Mexico, sometimes becoming weedy.[2] It flowers year-round, especially in spring,[2] and it may be in full flower at the end of the dry season.[1] It is admired for its yellow flower heads and is cultivated as an ornamental plant.[1] [2]
The plant is used in Mexican traditional medicine to treat fever and rheumatism.[5] In Chiapas it is used as an insecticide in corn supplies.[5] Secondary metabolites isolated from the species include pyrrolizidine alkaloids, lactones, furoeremophilanes, and sesquiterpenes.[5]