The seeds germinate in the summer; the plant spends its first 'year' as a low rosette of leaves close to the ground. The leaves are gathering energy; the plant is growing its long black taproot. After a winter's rest the plant puts on a few more leaves. When it has enough stored energy, it bolts—grows a central leader that will bear flowers. The leader grows one to three feet in height.

The flowers are borne on an unusual inflorescence, a thyrse. The central leader of a thyrse is indeterminate; its growth is not arrested by the opening of the first flowers. It continues growing until the plant wears itself out or cool weather intervenes.

The side branches are scirpoid cymes and are determinate. [The growing tips of the cymes appear like fringed green aprons below the blue flowers in the photo.] The flower buds are pink; the flowers open a brilliant blue and rarely purplish, pink, or white.

Beautiful and dramatic, viper's bugloss is not a wildflower to pick. The plant is covered with two types of trichomes, fine and coarse. The fine hairs cover most of the surface of the leaves and stem. The coarse bristles have swollen bases and extend from dark spots on the stem. Picking the flowers or even brushing against the plant is painful, causes a rash, and isn't a mistake one makes a second time.

(Compiled from: An Illustrated Flora of Northern United States and Canada, Nathaniel Lord Britton and Addison Brown, Dover, NY, 1970; Hortus Third, Staff L.H. Bailey Hortorium, NY State College of Agriculture and Life Sciences, Cornell University, Macmillan, NY, 1976; and "Viper's Bugloss or Blueweed (Echium vulgare L.)", Stephen F. Enloe, Weed Alert, Wyoming Pest Detection Program, University of Wyoming Cooperative Extension Service, 2004.)