Acanthocephalus benthamianus

This annual herb grows to a height of 10-50 (sometimes 70) cm. Its flowering stems are erect, hispid below, and often branched. Rosette leaves are oblong-obovate or obovate, with sinuate-dentate margins and a petiole-like base. Cauline leaves are oblong-ovate, sinuate-dentate or subentire, and either amplexicaul or attenuate. The peduncle is short, and the involucre is 5.0-7.0 mm in diameter and hispid. The achenes are ovoid in outline, laterally compressed, approximately 5.0 mm long and 1.5-1.8 mm wide, with tuberculate ribs and a color ranging from grey to reddish brown. They are attenuate into an ill-defined beak.