Dense stands of 4–16-inch tall Greenthread can cover fields and roadsides with waves of yellow. Look for numerous leaves divided into thread-like segments. Note the flower heads on long stems, notched ray flowers, and the radiating outer phyllaries at the base of the flower head, typical of the Thelesperma genus.

FLOWER: June–September. Flower stems (peduncles) 2 3/8–10 inches tall 6–25 cm) with a single flower head 1–1 1/2-inch wide (12-38 mm); each head has about 8 golden, petal-like ray flowers tipped with three rounded lobes; central disk either yellow or reddish-brown. Beneath the rays, 8 inner phyllaries, transparent in bud, are united to the middle to form a cup; 7–12 linear outer phyllaries radiate from the base and are at least half as long as the inner ones. The buds droop prior to opening.

LEAVES: Opposite stem leaves, numerous along lower 1/2–3/4 of stem. Blades 2–4 1/2-inches long (5–12 cm), thread-like, divided 1–3 times.

HABITAT: Sandy, gravelly, clay soils, roadsides, disturbed areas; shortgrass prairies, desert grasslands and scrub, pinyon-juniper, ponderosa-Douglas fir forests.

ELEVATION: 3,500–8,000 feet.

RANGE: AR, AZ, CO, KS, NE, NM, OK, SD, TX, WY.

SIMILAR SPECIES: Longstalk Greenthread, T. longipes, in the southern 1/2 of NM, has leaves crowded on the bottom 1/4–1/2 of stem and short outer phyllaries radiating beneath the rays. Slender Greenthread, T. simplicifolium, in so. NM, has leaves widely scattered on bottom 3/4 of stem, and radiating outer phyllaries less than half the length of the inner ones.

NM COUNTIES: Scattered throughout NM in low- to mid-elevation habitats: Bernalillo, Chaves, Cibola, Curry, Dona Ana, Eddy, Hidalgo, Lincoln, Los Alamos, Otero, Quay, Rio Arriba, Roosevelt, San Juan, San Miguel, Sandoval, Santa Fe, Socorro, Torrance.