Plants 30-150 cm, herbage glabrous. Stems usually 1, erect. Leaf blades 40-100 mm, bases narrowly decurrent, margins entire to spinulose-toothed, faces resinous. Heads usually in tight to loose, corymbiform arrays, rarely borne singly. Peduncles: ultimate 1-40 mm, minutely stipitate-glandular. Phyllaries minutely stipitate-glandular. Ray corollas 4-11 mm. Pappi (ray) 0, outer disc 0 or minute crowns, inner nearly 0 or minute crowns, sometimes lacerate or with awnlike scales 0.2-0.8 mm, rarely with ring of persistent, 15-20, antrorsely ciliolate bristles ca. 1.4 mm. 2n = 12.
Flowering (Jul-)Aug-Oct. Meadows, stream bottoms, ditches, grasslands, areas of oak-pine or pine woodlands, usually in habitats at least intermittently wet; 1100-2700 m; Ariz., Tex.; Mexico (Chihuahua, Durango, Jalisco, Sonora, Zacatecas).
FNA 2006, Martin and Hutchins 1980, Kearney and Peebles 1969, Wiggins 1964
Duration: Annual Nativity: Native Lifeform: Forb/Herb General: Stout herbaceous annual to 1.5 m tall, glutinous and sometimes sparingly tomentose in youth, very leafy to apex. Leaves: Lanceolate to oblong-lanceolate, 5-20 mm wide, 5-10 cm long, tapering toward each end, entire or sometimes sparingly denticulate, obscurely pinnately veined. Flowers: Heads numerous in corymbose cymes, radiate, pedicels stipitate-glandular, involucres hemispherical, 6-8 mm high, bracts linear to narrowly oblong, subequal, greenish and loose to slightly spreading at tips; ray flowers 12-19, ligules yellow, 4-5 mm long, about equaling tubes; disk flowers 40-60, golden yellow. Fruits: Cypselae oblong, compressed, those of rays glabrous, devoid of pappus; disk cypselae sparingly stiff hairs, with a very short, toothed, coroniform pappus on outer ones, inner usually with 4-8 longer, stiff paleae. Ecology: Found along arroyos, alluvial, and saline soils from 1,000-5,500 ft (305-1676 m); flowers August-October. Notes: This plant should be collected where it is appropriate to improve understanding of its distribution. Ethnobotany: Unknown Etymology: Xanthocephalum is from a Greek name meaning that which is dyed yellow and the word for head, while gymnospermoides means naked seed. Synonyms: Grindelia gymnospermoides, Gutierrezia gymnospermoides Editor: SBuckley, 2010