branched from the hairy base, glabrous above; branches erect, slender; leaves irregularly toothed; lower ones opposite, obovate or ovate-obtuse, middle ones alternate, ovate-lanceolate, acute, angustate at the base; bracteæ minute, linear; peduncles simple or dichotomous; tube of calyx glabrous, obovoid, as long as the lanceolate, ciliolate lobes; corolla infundibuliform, sub-5-fid, 3 times longer than the calyx; capsule obovoid, 3-celled. Very variable in habit and size; small specimens with ascendent, filiform branches 2–4 inches long, the largest more erect, 1 1/2–2 feet high, more or less branched. Leaves numerous at the base, but not rosulate, 4 lines to 1 inch long, 2–5 lines broad, the middle and upper ones denticulate or nearly entire. Peduncles much elongated, 1-flowered, filiform. Calyx 1–2 lines long. Corolla drooping in the bud state, white at the base; the lobes blue. Capsule in var. α. 2–3 lines long; in var. γ. 4 lines long, 1 1/2–2 lines broad.