Corolla white, pale to dark blue or purple, funnel-shaped or ± salver-shaped; tube as long as calyx or a little longer, lobes oblong, rounded or subtruncate, 1.5–2.5 mm. long, 1–2 mm. wide.
Calyx densely pale bristly; lobes erect, linear-subulate, 3–6 mm. long, becoming up to 0.8–1.5 cm. long in fruit, blunt or acute.
Cymes simple, terminal or several arising from the axils of the uppermost leaves, becoming lax and elongate in fruit; pedicels 1–3(–5 in fruit) mm. long and sometimes becoming markedly and asymmetrically incrassate in fruit.
Leaves linear-oblong, lanceolate, narrowly elliptic or oblanceolate, 0.8–4.5(–10) cm. long, 0.2–1.2(–2) cm. wide, acute to ± obtuse or rounded at the apex, sessile or somewhat amplexicaul at base.
Erect or decumbent annual (2–)6–40(–90) cm. tall, with mostly simple or branched thinly to densely adpressed-strigillose or patently setulose stems.
Nutlets whitish or pale brown, very hard and ± glossy, 2–3(–4) mm. long, 1.5–2.5 mm. wide, minutely to coarsely rugulose-tuberculate, without lateral swellings; beak short, blunt, slightly incurved.
Herb, 0.05-0.50(-0.90) m high. Indumentum of calyx whitish, calyx more than half as long as corolla tube, with long, sparse hairs, lobes acute. Corolla not longer than 10 mm. Nutlets tuberculate, brownish or greyish, not shining, with hard pericarp. Flowers white.
Greyish green, annual herb, up to 600 mm tall, densely covered with appressed bristles. Leaves narrowly ovate to obovate. Flowers in scorpioid cymes, white, corolla tube hairy inside, with scale-like lobes at base, calyx with a white indumentum, enlarging in fruit. Nutlets ± ovoid, rugose and tuberculate.
Roughly hairy annual to 60 cm. Leaves oblanceolate. Flowers in helicoid cymes, small, white. Nutlets ovoid, rugose-tuberculate.
Annual herb, up to 0.6 m high. Roots purplish red. Stems erect or decumbent, densely hairy. Leaves sessile; blade narrowly ovate or narrowly obovate, 15-45 x 3-8 mm, apex acute, margin entire, densely setulose. Flowers: bracteate; inflorescences terminal, cymes scorpioid; calyx > 1/2 as long as corolla tube, lobes with apices acute, indumentum whitish, hairs long, sparse; corolla with 5 well-differentiated, longitudinal bands of hairs extending from bases of lobes downwards to tips of anthers; stamens included, tube 5-7 mm long, white; Aug.-Nov. Fruit of 4 tuberculate nutlets, brownish or greyish, not shining, with hard pericarp.
Native of Eurasia, widespread naturalised weed in many parts of the world.