Parthenium ligulatum

Perennials, 1-2 cm (underground caudices 2-5+ cm, branched; plants cespitose or forming mats). Leaf blades oblanceolate to spatulate, 5-18+ × 1-2(-4+) mm, margins entire, faces strigilloso-sericeous (gray) and obscurely gland-dotted. Heads radiate, borne singly. Peduncles 0-4 mm. Phyllaries: outer 5 ± ovate, 2.5-3 mm, inner 5 ± orbiculate, 3-4+ mm. Pistillate florets 5; corolla laminae oval to elliptic, 1-2 mm, retuse. Disc florets 15-25+. Cypselae oblanceoloid to pyriform, 3.5-4 mm; pappus-like enations 2, erect to spreading, ± subulate, 0.5-1 mm (a third, ± subulate element sometimes at apex of adaxial face). 2n = 36, 72.

Flowering May-Jun. Pale shale or sandstone outcrops with pinyon-juniper; 1800-2000 m; Colo., Utah.