Toxicity can vary in a plant according to season, the plant???s different parts, and its stage of growth; and plants can absorb toxic substances, such as herbicides, pesticides, and pollutants from the water, air, and soil.Flower March - April (in south); June (in north).Flower March - April (in south); June (in north)Habitat Prairies; open woods.Range S. Michigan to Minnesota and se.