Plants annual. Leaves 1-2-pinnate; segments lanceolate to oval. Involucre of 1-5 linear to lanceolate bracts or lacking. Rays 2-5. Flowers white to purple; central flower in an umbellet male. Fruit laterally compressed; dorsal, interme¬diate and secondary ridges with 2-3 rows of prickles; lateral ridges on the commis¬sural side with a row of prickles; vittae solitary under the secondary ridges. Inner seed face involute.