Branching herbs or subshrubs. Stems terete, minutely striate, older ones covered with brown or gray bark exfoliating in thin strips. Leaves sessile or petiolate; blades linear to lanceolate, punctate, cystoliths common on upper surface. Inflorescences racemose or paniculate, flowers borne singly or several at a node, secund or opposite; bracts and bracteoles mostly triangular to linear, usually caducous, similar to calyx in pubescence. Calyx subequally 3-5-lobed, lobes triangular to linear, glabrous to pubescent; corolla usually red, mostly pilose, tubular to funnelform, more or less arcuate, somewhat inflated at base, 2-lipped, usually recurved, posterior lip entire or slightly emarginate, anterior lip 3-lobed; stamens 2, epipetalous anteriorally, usually at base of central lobe of anterior lip, filaments more or less thick and fleshy, colored, glabrous, anthers 2-thecous, subequal, inserted at same level or nearly so, parallel or slightly divergent at base, connected to middle or slightly below, not mucronate or appendaged; style, glabrous, about as long as corolla, stigma simple, 2-lobed. Capsules subpyriform, slightly beaked, usually narrowed at base to form a relatively distinct stipe, glabrous and shiny; seeds 2-4, diskoid, more or less tuberculate, each supported by a curved retinaculum usually at about same height in body of capsule.
Argentina present, Guianas present, New World present, SW United States present, South America present, Southern America: Argentina Northwest (Jujuy present), arid and semi-arid portions of Mexico present
About 15 New World species, ranging from the arid and semi-arid portions of Mexico and adjacent SW United States into South America to Argentina (Jujuy); 1 species in the Guianas.