Mexican Gumweed

Annuals (biennials), 20–55 cm. Stems erect, stramineous, glabrous. Cauline leaf blades obovate or oblong to spatulate, (5–)10–15(–30) mm, lengths 2–2.5(–5) times widths, bases ± clasping, margins crenate (teeth usually 7–9, sometimes 3–6, per cm, rounded to blunt, usually resin-tipped), apices obtuse to acute, faces glabrous, moderately gland-dotted. Heads in open, paniculiform arrays or borne singly. Involucres broadly urceolate, 7–10 × 8–16 mm. Phyllaries in 4–5 series, reflexed to spreading, ± lanceolate, apices recurved to nearly straight, subulate to acuminate, moderately to strongly resinous. Ray florets 20–30; laminae 7–9 mm. Cypselae brown, 1.5–3 mm, apices smooth or coronate, faces rugose; pappi of 2–3 straight, smooth or barbellulate (distally dilated), setiform awns 4–6 mm, shorter than or nearly equaling disc corollas. 2n = 12 (Mexico).

Grindelia oxylepis, the Mexican gumweed, is a North American species of flowering plants in the family Asteraceae. It is native to northern Mexico, in the States of Chihuahua, Coahuila, Durango, San Luis Potosí, and Zacatecas. The natural range barely crosses the Río Grande into the United States, with a few populations in western Texas and southern New Mexico

Grindelia oxylepis grows in moist valleys and fields. It is an annual or biennial herb up to 55 cm (22 in) tall. The plant usually produces numerous flower heads in open, branching arrays. Each head has 20-30 ray flowers, surrounding a large number of tiny disc flowers.