Herbs annual. Roots with purple dye. Stems usually single, branched from base or only above, 15-30 cm tall, short strigose. Leaf blade oblanceolate to linear, 2-4 cm × 3-7 mm, short strigose, apex acute. Cymes terminal, to 10 cm; bracts same shape as leaves but smaller. Flowers sparse, short pedicellate. Calyx lobes usually erect, linear, 4-5.5 mm, to 1.1 cm in fruit, short strigose on both sides, base becoming slightly hardened. Corolla white, sometimes blue or light blue, salverform; tube ca. 4 mm, sparsely pubescent outside; throat with 5 bands of hair extending to tube; limb ca. 1/2 as long as tube; lobes somewhat unequal, erect to slightly spreading, ovate or oblong, ca. 1.5 mm. Stamens attached below middle of tube; anthers oblong, ca. 1 mm. Style 1.5-2 mm; stigma capitate. Nutlets gray-brown, triangular-ovoid, ca. 3 mm, finely tuberculate. Fl. and fr. Apr-Aug. 2n = 14, 28, 36, 42.
A highly variable species with several infraspecific taxa recognized in Europe.
"Strigose annual 1–8 dm, often branched at the base; lvs mostly linear to narrowly oblanceolate, 3–8(–15) mm wide, acute or obtuse, 1-nerved; fls solitary in the crowded upper axils, becoming remote, whitish or bluish-white, 5–8 mm, 2–4 mm wide; cal-lobes nearly as long as the cor; nutlets ovoid, pale dull brown, 3 mm, deeply wrinkled and pitted; 2n=28. Native of Eurasia, intr. as a weed of waste places over most of the U.S. Apr.–July. (Buglossoides a.)"