| Noun | 1. | genus Allionia - small genus of chiefly American herbs caryophylloid dicot genus - genus of relatively early dicotyledonous plants including mostly flowers Allioniaceae, family Allioniaceae, family Nyctaginaceae, four-o'clock family, Nyctaginaceae - a family of flowering plants of the order Caryophyllales Allionia incarnata, trailing four o'clock, trailing windmills - trailing plant having crowded clusters of 3 brilliant deep pink flowers resembling a single flower blooming near the ground; found in dry gravelly or sandy soil; southwestern United States and Mexico |