J. Phys. Chim. Hist. Nat. Arts 89: 99. 1819. 1819
Herbs, annual or biennial, possibly sometimes perennial; hemiparasitic. Stems erect, not fleshy, puberulent, retrorsely puberulent, or pubescent. Leaves loosely basal and cauline, opposite; petiole present; blade not fleshy, not leathery, margins pinnatifid to 2-pinnatifid proximally, sometimes entire distally. Inflorescences terminal or terminal and axillary, spikelike racemes; bracts present. Pedicels present; bracteoles absent. Flowers: sepals 5, calyx weakly bilaterally symmetric, campanulate, lobes ovate to oblong-ovate; petals 5, corolla yellow, bilabiate, campanulate, abaxial lobes 3, adaxial 2; stamens 4, didynamous, filaments lanate, anthers glabrous; staminode 0; ovary 2-locular, placentation axile; stigma capitate or 2-lobed. Capsules: dehiscence loculicidal. Seeds 50–100, tan or brown, angled, wings absent.
e, nc United States.