About Oxytheca perfoliata Torr. & A.Gray
Oxytheca perfoliata Torr. & A.Gray is a species of flowering plant in the buckwheat family. It has two common names: round-leaf puncturebract and roundleaf oxytheca. This species is native to the southwestern United States, where it commonly grows in deserts, plus some woodland and valley areas. It is an annual herb. In spring, it grows a leafless stem that reaches a maximum height of around 20 centimeters. During winter, the plant exists as a small rosette of oblong or spoon-shaped leaves, which are a few centimeters wide. The plant's tissue is red-veined green, but it often takes on colors from brown to maroon or magenta. The inflorescence at the top of the stem has nodes where bracts fuse to form a cup or band up to about 2.5 centimeters wide. At the end of each stem branch, there is a similar cup of partially fused bracts that surrounds a cluster of flowers. The bracts have sharp spinelike awns at their tips. The flowers range in color from white to yellow-green, and have a hairy texture.