This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Biennial or perennial mostly bristly-hirsute branching herbs, with alternate leaves, and rather large blue violet or rarely white flowers, in leafy-bracted scorpioid spikes. Calyx 5-parted, the segments narrow. Corolla tubular-funnel form, irregular, the limb unequally 5-lobed, the lobes rounded, spreading, the throat not appendaged. Stamens 5, inserted low down on the tube of the corolla, unequal, at least the longer ones exserted; filaments slender, dilated at the base; anthers ovate or oblong. Ovary 4-divided; style filiform, 2-cleft at the summit. Nutlets 4, erect, ovoid, rugose, attached by their bases to the flat receptacle, the scar of attachment not concave. [Greek, a viper.]
About 30 species, natives of the Old World. Type species: Echium italicum L.
Echium vulgare L. Sp. Pl. 140. 1753.
Bristly-hairy, biennial; stem erect, at length much branched, 1°-21/2° high. Leaves oblong, linear-oblong, or linear-lanceolate, obtuse or acute, entire, 2'-6' long, sessile, or the lower and basal ones narrowed into petioles; flower-buds pink; flowers bright blue, varying to violet purple, 8"-l2" long, numerous in short 1-sided spikes, forming a narrow thyrsus; calyx-segments much shorter than the corolla; limb of the corolla oblique, the lobes very unequal.
In fields and waste places, Nova Scotia to North Carolina, Ontario and Nebraska. A troublesome weed in some sections of the North. Naturalized from Europe. Native also in Asia. June-July. Viper's-herb. Viper's-grass. Snake-flower. Blue thistle. Blue stem or cat's-tails. Blue devils. Adder's-wort.