Erect herbs. Stipules adnate to the petiole. Leaves alternate, imparipinnate; leaflets dentate. Inflorescences composed of spike-like racemes. Flowers 5-merous. Calyx with numerous hooked spines below the lobes. Petals 5, yellow. Disk annular. Stamens (in ours) 10-15. Carpels 2. Achenes usually 2, enclosed in the hardened calyx lobes which bears hooked prickles.