Moab woody-aster

Xylorhiza glabriuscula Nuttall var. linearifolia T. J. Watson, Brittonia 29: 215. 1977; Machaeranthera linearifolia (T. J. Watson) Cronquist

Subshrubs, 15–35 cm. Stems branched mostly in proximal ³ / 4 , puberulent to coarsely stipitate-glandular. Leaves: blades linear-oblong to linear-lanceolate, (2–)2.5–5 mm wide, bases truncate or rounded-auriculate, margins flat, usually entire, rarely few-toothed, faces puberulent to coarsely stipitate-glandular. Peduncles 3–11 cm. Involucres 10–17 × 15–30 mm. Ray florets 13–21; corollas light blue to white. Style-branch appendages slightly shorter to ± equaling stigmatic lines. 2n = 12, 24.

Flowering Apr–May(–Jun). Deep canyons, sands, and clays; 1300–2000 m; Utah.

Xylorhiza linearifolia is known from Garfield, Grand, San Juan, and Wayne counties. Plants with few-toothed leaf margins may be indicative of hybridization with X. tortifolia, which is sympatric with X. linearifolia in the southern part of its range.