Flower arrays on stems reaching 2-feet tall have 1–3 flower heads with white or light-blue to purple rays, and a yellow disk with oval to leafy phyllaries cupping the base. Note the broad, clasping, leaves  alternating along the stems. This highly variable species has 3 varieties in NM with rows of leaf-like to linear phyllaries.

FLOWERS: July–October. Flower heads have 15–60 petal-like rays, pale-blue to violet, 1/4–3/4-inch long (8–18 mm); disk flowers yellow; phyllaries variable according to varieties: the 8-inch tall var. apricum has purple-tinged, oblong to linear phallaries with pointed tips, inner and outer rows of equal length; the 8–12 inch tall var. parryi has green, oblong to linear phyllaries with phyllaries in the inner and outer rows of equal length; the 8–24 inch tall var. canbyi has phyllaries with rounded tips, often leaf-like, with outer the phyllaries longer than the inner ones.

LEAVES: Basal and alternate on stem. Basal leaves usually present at flowering. Stem leaves alternate, lance-shaped to elliptic, 1 3/8–4 3/4-inches long (3.5–12 cm), smaller size up the stem, stemless or clasping, tips pointed, usually hairless, margins entire or serrated.

HABITAT: Moist soils, mountain meadows, streambanks; alpine and subalpine meadows, aspen, spruce-fir forests.

ELEVATION: 6,800–11,600 feet.

RANGE: Widespread in Rocky Mountains and all states west.

SIMILAR SPECIES: Lance-leaf Aster, S. lanceolatum, a wetland obligate in central and northern mountains, has light-colored phyllaries  with green tips, leaf-like bracts at the base of the peduncle (flower stem), and 1/2-inch wide flower heads with white to dark-blue rays. Smooth Blue Aster, S. laeve, in much the same habitat and range, is hairless with narrow (not broad), clasping stem leaves.

NM COUNTIES: Northern mountains in high-elevation, moist habitats: Catron, Cibola, Lincoln, Los Alamos, McKinley, Mora, Rio Arriba, San Juan, San Miguel, Sandoval, Santa Fe, Sierra, Socorro, Taos.