Perennials or subshrubs, 20-50+ cm. Leaves pinnately lobed, 15-40 mm, lobes 3-5, linear to cuneate or oblanceolate (oil-glands at base of each lobe and subterminal in tips). Peduncles 20-80 mm. Calyculi of 12-16 subulate bractlets 3-8 mm (bearing glands). Involucres obconic, 10-15 mm. Phyllaries 12-20, lanceolate, separating in fruit. Ray florets 10-14; corollas yellow, becoming red-orange; tubes ca. 2 mm, laminae 6 × 2 mm. Disc florets 25-40; corollas yellow-orange, 7-8 mm. Cypselae 5 mm; pappi of 8-12 scales 7-8 mm, each comprising 7-11 basally connate bristles. 2n = 26.
Flowering spring and fall. Alluvial fans and rocky slopes in deserts; 0-1200 m; Ariz., Calif., Nev.; Mexico (Baja California, Sonora).
Duration: Perennial
Nativity: Native
Lifeform: Subshrub
General: Perennial 20-50 cm tall from a thick woody base, herbage has a strong disagreeable odor; stems erect or ascending, glabrous, angled.
Leaves: Opposite below, alternate above, thick, pinnately lobed, 15-40 mm, lobes 3-5, linear to cuneate or oblanceolate with oil glands at the base of each lobe and subterminal in tips).
Flowers: Corymbose on peduncles 20-80 mm long, heads 1.5-2 cm long at anthesis; turbinate, obconic involucres, 10-15 mm; phyllaries 12-20, lanceolate, separating in fruit, acute to short-mucronate at apices; 10-14 ray florets, corollas yellow becoming red-orange, tubes about 2 mm; 25-40 disc florets, corollas yellow-orange, 7-8 mm.
Fruits: Brownish cypselae 5 mm, finely striate, srigillose, with pappus of 8-12 scales 7-8 mm, each comprising 7-11 basally connate bristles.
Ecology: Found on rock slopes, outwash fans, arroyos, and mesas below 4,000 ft (1219 m); flowers March-October.
Distribution: AZ, CA, NV; south to n MEX (Sonora, Baja California)
Notes: The smell of this species is clearly one of the more recognizable features, along with the oil glands at the base of the leaves.
Ethnobotany: Unknown
Etymology: Adenophyllum is from the Greek for gland-leaf, while porophylloides means having leaves like those of Porophyllum.
Synonyms: Dyssodia porophylloides
Editor: SBuckley, 2010
