stem ascendent or erect, branched, hairy at the base, naked and glabrous at the apex; leaves sessile or somewhat clasping, alternate, rarely opposite, ovato-oblong or ovato-lanceolate, coarsely crenated or toothed, sinuated and undulated, marginate; peduncles elongated, few flowered, rarely repetito-dichotomous; calyx glabrous; tube obconical; lobes ovate, acute, or acuminate, ciliolate; corolla large, 5-fid, infundibuliform, 3–4 times longer than the calyx; capsule obconical, 2 or 3-celled, striate. A rigid annual, well known from all the other species by the undulate, crenated, coriaceous, margined leaves. Stem 1/2–1 feet high, subangulate by the decurrent leaves; much leafy from the base, and generally clothed with white spreading hairs; branches as long, or often much longer than the stem, naked or leafy at the base, terminated by the quite naked, simple, or near the apex, 2–3-times forked, peduncles, each of which bears 2–5 pedicellate flowers. Leaves spreading, about 1 inch long, 3–4 lines wide, larger or smaller in different specimens, hairy, especially in the young, not flowering branches, but sometimes quite glabrous; upper ones gradually smaller and narrower, those at the base of the peduncles 3–1 line long, entire. Pedicels in flower short, in fruit 1/2–1 inch long, glabrous as the peduncles and flowers. Calyx variable in size, 1–3 lines long; lobes mostly broad, acute, shorter than tube, but sometimes as long or a little longer, acuminate. Corolla blue, 1/2–1 inch in diameter, with acute lobes. Style with two glands below the stigma. Capsule 4–6 lines long, 10-nerved, crowned by the erect short calycine lobes. Valves 2 or 3 in the same peduncle. Seeds oblong or ovoid. It varies also, but rarely with 1 flowered, much elongate peduncles, and flattish, but always distinctly undulate leaves.
