EcoFlora - Arctotheca calendula

Arctotheca calendula (L.) Levyns
Family: Asteraceae Fertile Capeweed [Cryptostemma calendulaceum (L.) R. Br.] Arthur Chapman	FNA Resources Alison McKenzie Mahoney in Flora of North America (vol. 19, 20 and 21) Plants usually stoloniferous. Leaves obovate, (2-)5-20(-30+) × (1-)2-5(-7) cm, margins pinnati-sect (lyrate to runcinate), remotely prickly, abaxial faces white-pannose, adaxial faces sparsely puberulent to arachnose, usually glandular as well. Heads 4-7 cm diam. (across the rays). Phyllaries: outer reflexed, apices mucronate, white-woolly; inner appressed, margins hyaline, apices rounded, glabrous. Ray florets 11-17(-25); corolla laminae abaxially greenish to purplish, adaxially yellow (drying to basally ochroleucous, apically blue, forming bull´s eye around disc), 10-25 × 2-4 mm, sparsely puberulent, glandular. Disc florets: corollas yellow proximally, bluish distally. Cypselae dark brown, 3 mm, densely woolly; pappi ca. 0.5 mm (usually hidden by hairs on cypselae). Flowering Oct-Aug. Roadsides, old fields, other disturbed habitats; 0-300 m; introduced; Calif.; Africa. Most populations of Arctotheca calendula are sterile and spread aggressively by stolons; at least three populations in the flora are fertile and highly invasive. The species is listed by the California Exotic Pest Plant Council (CalEPPC) as a weed with the potential to spread explosively (Red Alert, CDFA A).
Open Interactive Map Donald Hobern Donald Hobern Valter Jacinto University of Florida Herbarium University of Florida Herbarium Click to Display 41 Total Media