Shrubs [herbs], 20–300+ cm (often rhizomatous, stems hairy, hairs gland-tipped and glandless). Leaves cauline, usually ascending, almost parallel with stem; sessile or petiolate; blades elliptic, lanceolate, linear, or linear-lanceolate, bases cuneate, margins dentate or entire, faces (at least abaxial) usually glandular and ± strigose, stomates on both faces. Heads quasi-radiate (see florets), borne singly or in corymbiform or paniculiform arrays. Involucres ± cylindric, 12–15 mm (subtended by calyculi of 3–7 spreading or ascending bractlets). Phyllaries (reflexed in fruit) in 1–2 series, linear (± keeled), apices acute. Receptacles flat, smooth, hairy, epaleate. Florets 4–25[–60], bisexual, fertile; corollas yellow (aging white), zygomorphic (2-lipped; outer lip liguliform, lobes 3, lance-deltate, inner lip smaller, lobes ± filiform, recurved); anther basal appendages entire, apical appendages oblong, acute; style branches relatively short, apices truncate-penicillate. Cypselae subcylindric to fusiform, often ± beaked, ribs 5, faces glandular-hairy, papilla-like double hairs of cypselae producing mucilage when wetted; pappi of 60–80+ dull white [tawny], finely barbed bristles. x = 9.
Wiggins 1964, FNA 2006, Benson and Darrow 1981, Kearney and Peebles 1969
Common Name: American threefold Duration: Perennial Nativity: Native Lifeform: Subshrub General: Profusely branched shrub to 1 m or less, slender, brittle branches, appressed-puberulent branchlets, new growth glandular and often densely pubescent with brown hairs. Leaves: Leaves and flowers appear at various seasons, leaves mostly 3-8 cm, upright, blades relatively thin, lanceolate, with minute hairs to sometimes glabrate, densely glandular below and sometimes above but not as densely so, the margins toothed to nearly entire; sessile or petioles mostly 1-2 mm, usually winged, dead leaves semipersistent. Flowers: Heads in corymbose panicles, usually 12-14-flowered, inner phyllaries green, 10-15 mm, oblong, with thickened yellow-brown bases extending into midrib; flowers yellow, corollas 1 cm long, sparsely puberulent at tips of lobes. Fruits: Cypselae 8-10 mm long, slender, densely glandular with short stout hairs, pappus twice as long as achenes. Ecology: Found on rocky slopes and ridges below 5,000 ft (1524 m); flowers February-June, rarely flowers again in autumn. Distribution: s CA, AZ, s NM, sw TX; south to c MEX. Notes: Distinguished by being a medium-sized shrub with dark-green, lanceolate leaves which are densely glandular-dotted beneath and can be sticky, especially when young, and with corky thickened bracts below petioles; the single row of phyllaries, appearing as if they were just unfolded; and the showy orange-yellow bilabiate flowers in heads, with one ray smaller than the other. Ethnobotany: Unknown Etymology: Trixis is from Greek trixos, three-fold, referring to three-cleft outer corolla lip, while californica refers to California. Synonyms: None Editor: SBuckley 2010, FSCoburn 2015