Plectocephalus rothrockii
Madrean Star Thistle
Family: Asteraceae
This is an annual or biennial plant that grows 2-5’ tall, depending on conditions. Looks like a small, weedy chicory at first, until it starts to shoot up and bloom. The large, fringy flowers are purple and white and quite showy.
Plant behind other plants to obscure until it blooms, and account for its large size when it goes to flower. Full sun to shade, avoid reflective heat. Moderate to regular water. Very cold hardy. This is a short-lived perennial or annual, so save the seeds (they grow easy from seed), or allow to reseed in the garden.
This is basically a thistle, so the flowers attract a wide variety of birds, bees, butterflies, and many other nectar-seeking insects. Granivorous birds like goldfinches love the seeds of this plant.
The genus has a long history of medicinal use.
The genus name, Plectocephalus, comes from the Greek plektos, woven, and kephale, head, alluding to interwoven fringes of phyllaries. The species name, rothrockii, is named for Dr. Joseph Trimble Rothrock (1839-1922), surgeon on the Wheeler expedition of 1873-1875.
Found in damp soil near streams, roadsides, open pine-oak woodlands and forests, from 4,500-9,500 ft in the mountains of Arizona and New Mexico, south along the Sierra Madre Occidental mountains of Mexico (Chihuahua, Durango, Sinaloa, Sonora).
Flower detail, photo by Liz Makings, SEINET
Very typical habitat, Tamazula, Durango, in Mexico. Photo by J. Fernando Pío León, iNaturalist
A photo showing the growing nature of the plant, as well as some typical habitat, in the Chiricahua Mountains, Arizona. Photo by J. Richard Abbott, iNaturalist