Amsonia angustifolia Michaux var. texana A. Gray in A. Gray et al., Syn. Fl. N. Amer. 2(1): 81. 1878

Stems basally ascending to erect, glabrous; branches usually at most equal to infructescence (but occasionally becoming very long). Leaves: petiole 1–3(–4) mm in stem leaves, 0–1 mm in branch leaves; stem leaf blades narrowly elliptic to elliptic (ligulate), (3–)3.5–6.5 cm × (3.3–)5–15 mm, margins slightly to strongly revolute, not or occasionally ciliate, apex acute to acuminate; branch leaf blades linear to very narrowly elliptic, 3.2–5.6 cm × 2–6 mm, margins often much more deeply revolute than on stem leaf blades. Flowers: sepals narrowly deltate, apex acuminate or acute, 1–1.5(–2) mm, sparsely ciliate with long hairs or glabrous; corolla tube (6–)7–9(–10) mm, lobes (5–)6–8(–9) mm, margins often minutely ciliate. Follicles (7–)11–13.5 cm × 3–4 mm.

Flowering spring; fruiting summer. Prairies, pastures, post oak woodlands, hills, rock outcrops, stream banks, along roadsides and railroad tracks; 200–900 m; Okla., Tex.

Variety texana is distinguished from var. ciliata by leaf margins that are usually not ciliate, often broader leaves (especially branch leaves), and often ciliate corolla lobes. It occurs in the hill country of Texas and Oklahoma, geographically separated from and at higher elevations than var. ciliata.