Annual to perennial herbs with leaves opposite or whorled, entire, toothed or pinnatifid exstipulate. Flowers small, in dense bracted and involucrate heads or interrupted spikes. Calyx cup-shaped, discoid or divided into spreading bristles. Corolla limb 4-5 lobed. Stamens 2-4 inserted on throat of corolla. Ovary inferior, 1-loculed; style filiform; stigma simple. Ovule 1. Fruit an achene. (Munz, Flora So. Calif. 395)
Upper Newport Bay species within the family: