Kearney’s blue-star

Stems erect, 39–62(–90) cm, moderately (densely or sparsely) long-pubescent; branches borne on distal part of stem, often exceeding infructescence. Leaves: petiole 1–3(–5) mm, densely to moderately pubescent (glabrous); blades heteromor­phic; stem leaf blades lanceolate to narrowly lanceolate (narrowly oblong-elliptic), 5–7.6 cm × 11–17 mm, margins entire, often slightly revolute, ciliate with usually long cilia (rarely not ciliate), apex acute to acuminate, surfaces long-pubescent on midrib and main veins (rarely glabrous) adaxially; branch leaf blades narrowly lanceolate, 4.3–5.7 cm × (3–)6–9 mm. Flowers: sepals subulate, (3–)4–5(–6) mm; corolla tube green to purplish, 12–14(–15) mm, lobes white, (2–)3–4 mm, outer surface of corolla glabrous. Follicles erect, 3–10 cm × 3.5–5.5 mm, apex short-acuminate, glabrous. Seeds 6–11 × 3–4(–4.8) mm.

Flowering spring; fruiting summer. Canyons, plains, hillsides near streams; of conservation concern; 1100–1600 m; Ariz.

Amsonia kearneyana is endemic to the Baboquivari Mountains in Pima County; it is listed as endangered. The species is notable for its often densely long-pubescent pedicels and inflorescences and unusually short corolla lobes. These features are not unknown in the widespread and variable A. palmeri, although spec­imens of that species with corolla tubes longer than 12 mm are uncommon and typically have longer corolla lobes. The seeds of A. kearneyana are broader than those of any other species of subg. Sphinctosiphon.