T. maximum: annual; stems erect, two feet or more high, rough with short, stiff hairs; leaves pinnate, with 5-9 lanceolate, almost ovate, coarsely toothed segments; umbels terminal, of 8-10 short rays, with a few rather long, narrow bracts to the involucres; petals small pink. - Waste and cultivated lands; rare. Fl. June, July.