Oxytheca perfoliata
English: Round-leaf puncturebract; Roundleaf oxytheca.
Region: southwestern United States.
Habitat: deserts, woodland, valley areas.
Botany: annual herb; leafless stem up to about 20 centimeters in maximum height in the spring; during the winter the plant is a small rosette of oblong or spoon-shaped leaves a few centimeters wide, red-veined green, often brown to maroon or magenta; inflorescence atop, punctuated by nodes at which the bracts are fused to form a cup or band ± 2 centimeters wide; cup of bracts partially fused around a cluster of flowers; bracts tipped in spinelike awns; flowers white to yellow-green; hairy.