Erect or decumbent, annual or perennial, glabrous in most parts, shining, smooth, 1/2–3 feet long. Branches dichotomous, slender, herbaceous. Leaves lanceolate, acute, faintly nerved, subscabrous, wedge-shaped at the subsessile base; 3/4–1 1/2 by 1/8– 1/2 in.; stipules very short and truncate or ovate, subciliate. Flowers tetramerous, 1/4– 1/3 in. long, much exceeding the calyx, deep blue or lilac, pedicellate, in lax or divaricate mostly terminal cymes (a solitary flower often occurs in the forks of the branches). Calyx small; teeth lanceolate-subulate as long as the tube. Corolla salver-shaped; tube much exceeding the calyx, slender below, funnel-shaped above; limb 1/6 in. diameter; lobes ovate, subobtuse; throat thinly pubescent. Anthers subexserted. Fruit toughly coriaceous, subglobose, shining, 1/12– 1/8 in. diameter, subdidymous, at length bursting from the apex loculicidally. Seeds obtusely angular.
