WILDFLOWERS OF NEW MEXICO

This resinous, 1–3-foot tall, bushy plant often forms dense stands. Look for hairless stems and leaves with rounded teeth. Flower heads may not have petal-like rays; yellow disks, especially buds,  are white with resin, and stems range from green to gray or red. This widespread species has numerous variations.

FLOWER: July–September. Open arrays of gummy flower heads cover the branch tips. Sometimes the 3/8–3/4-inch (8–20 mm) wide central disk is white with sticky resin. Yellow, petal-like ray flowers are often absent, but plants may have 24–36 showy yellow rays. The florets grow out of a rounded cluster of slender, curved to hooked phyllaries at the base of the head, also resinous.

LEAVES: Alternate. Blade oblong to lance-shaped, 5/8–2 3/4-inches (15–70 mm) long at midstem and smaller upward; surfaces hairless, strongly gland-dotted; margins with blunt, rounded or serrated teeth; middle and upper leaf bases mostly clasp the stem.

HABITAT: Dry to moist sandy, rocky soils of fields, roadsides, disturbed areas; grasslands, sagebrush, pinyon-juniper-oak, ponderosa woodlands.

ELEVATION: 3,800–8,000 feet.

RANGE: Widespread west of the Mississippi River.

SIMILAR SPECIES: 7 species of Grindelia in NM. This species now includes the once separate, G. nuda (with hairless red stems, no ray flowers). Arizona Gumweed, G. arizonica, in central, western NM, has hairless red stems, 8–26 yellow ray flowers if present, straight, lance-shaped phyllaries, and non-clasping leaves. Rough Gumweed, G. scbra, in southwest quarter of NM, has hairy stems, yellow rays, slightly curved phyllaries, and leaf margins with sharp teeth. Hairy Gumweed, G. hirsutula, in west-central NM, has hairy or hairless stems, leaves with serrated or sharp teeth, looped or hooked, strongly resinous phyllaries, and yellow ray flowers.

NM COUNTIES: Nearly statewide (not recorded in Luna Co.) in low- to medium-elevation, dry habitats.