Orcutt’s woody-aster

Aster orcuttii Vasey & Rose, Bot. Gaz. 16: 113. 1891; Machaeranthera orcuttii (Vasey & Rose) Cronquist & D. D. Keck

Shrubs, 50–150 cm. Stems branched to near apices, glabrous (younger stems and branchlets glabrous, eglandular). Leaf blades spatulate to oblong or lanceolate, 5–26 mm wide, bases attenuate to cuneate or subauriculate-subclasping, margins flat, spinulose-dentate to subentire, faces glabrous or sericeous along veins. Peduncles 1–7 cm. Involucres 17–20 × 20–45 mm. Phyllaries tightly appressed, outermost glabrous, innermost equaling or longer than mid. Ray florets (18–)27–38(–45); corollas light blue to lavender. Style-branch appendages shorter than stigmatic lines. 2n = 12.

Flowering (Nov–)Jan–Apr(–Jun). Slopes and ravine bottoms, rocky sand and clay of high pH, in relatively barren areas dominated by creosote bush and cactus; of conservation concern; 20–300 m; Calif.; Mexico (Baja California).

Xylorhiza orcuttii grows in Imperial, Riverside, and San Diego counties.