1. Echium vulgare L. (blueweed, blue devil, blue thistle)

Map 1294, Pl. 305 a, b

Plants biennial, with taproots. Stems 30–80 cm long, erect or ascending, solitary or occasionally few, usually unbranched below the inflorescence, densely pubescent with minute, usually downward-pointed hairs and scattered to dense, longer, stiff, strongly pustular-based hairs. Leaves alternate and basal, the basal leaves sometimes withered at flowering and with the blades tapered at the base to a short or long petiole, the stem leaves mostly sessile and progressively reduced toward the stem tip. Leaf blades 2–25 cm long, 5–30 mm wide, those of the basal and lower stem leaves oblanceolate to narrowly oblanceolate, those of the median and upper leaves narrowly oblong to narrowly lanceolate or occasionally nearly linear, tapered to angled or rounded at the base, mostly angled or short-tapered to a sharply pointed tip, the surfaces and margins moderately to densely pubescent with stiff, bristly, spreading to somewhat ascending, pustular-based hairs. Stem leaves short-petiolate to sessile, the blade 1–7 cm long, 2–8 mm wide, linear to narrowly lanceolate, angled or tapered at the base, without noticeable lateral veins, otherwise similar to those of the basal leaves. Inflorescences spikelike, scorpioid spikes, these aggregated into a short or elongate panicle, the branch points with leaflike bracts 1–6 cm long, the flowers with short, leaflike bracts, sessile or nearly so. Cleistogamous flowers not produced. Calyces more or less actinomorphic (2 of the lobes sometimes slightly reduced), 5-lobed nearly to the base, the lobes 5–7 mm long at flowering, sometimes becoming elongated to 6–10 mm at fruiting, narrowly triangular to narrowly lanceolate, bristly-hairy, persistent and ascending at fruiting. Corollas 12–20 mm long, more or less funnelform, zygomorphic, the upper 2 lobes longer than the other 3, bright blue (pink in bud), the tube 8–12 mm long, the throat lacking scales, the lobes 2–5 mm long, more or less ascending, rounded to bluntly pointed, hairy on the outer surface. Stamens attached at different levels below the midpoint of the corolla tube, the filaments elongate (1 shorter than the others), the anthers oblong to somewhat heart-shaped, long-exserted from the corolla (the shortest stamen only slightly exserted). Ovary deeply 4-lobed, the style long-exserted from the corolla, finely hairy, usually withered at fruiting, the stigma capitate, strongly 2-lobed. Fruits dividing into mostly 4 nutlets, these 2.0–2.8 mm long, erect to slightly oblique, angular-ovoid with a relatively sharp ventral keel, attached to the relatively flat gynobase at the base or nearly so, the attachment scar surrounded by a collarlike ring, bluntly pointed at the slightly oblique tip, the surface strongly longitudinally wrinkled and warty or tuberculate, dark brown to nearly black with tan to white raised areas. 2n=16, 32. May–September.

Introduced, scattered, mostly in the eastern half of the Ozark and Ozark Border Divisions (native of Europe, introduced nearly throughout the U.S. [including Alaska] and Canada). Banks of streams and rivers, upland prairies, and openings of mesic upland forests; also pastures, railroads, roadsides, and open, disturbed areas.

Echium is distinguished from other Missouri genera of Boraginaceae by its irregular, oblique corollas and unequal, purple stamens. Pusateri and Blackwell (1979) studied morphological variation in introduced North American populations and concluded that it is impossible to delineate infraspecific taxa within the species. As with many other members of the Boraginaceae, the species contains toxic pyrrolizidine alkaloids (Burrows and Tyrl, 2001) and might become a problem for livestock if it were to spread into an overgrazed pasture from an adjacent roadside.