Smooth woody-aster

Aster parryi A. Gray; Machaeranthera glabriuscula (Nuttall) Cronquist & D. D. Keck; M. glabriuscula var. villosa (Nuttall) Cronquist & D. D. Keck; Xylorhiza glabriuscula var. villosa (Nuttall) A. Nelson; X. villosa Nuttall

Subshrubs, 10–25 cm. Stems branched mostly in proximal ³ / 4 (leafy ² / 3 + their lengths), villoso-puberulent or glabrous, eglandular. Leaf blades oblanceolate, 2.5–8 mm wide, bases attenuate, not clasping, margins flat, entire, faces villoso-puberulent or glabrous, eglandular. Peduncles 2–6 cm. Involucres 7–14 × 12–25 mm. Ray florets 12–25; corollas white. Style-branch appendages equal or shorter than stigmatic lines. 2n = 12.

Flowering May–Jun(–Jul). Open sites, selenious, alkaline clays, dominated by sagebrush, saltbush, greasewood, and grasses; 1100–2300 m; Colo., Mont., S.Dak., Utah, Wyo.