Subshrubs, 8-22 cm (rounded or flat-topped). Stems greenish, much branched, strigillose. Leaf blades 1- or 3-nerved (some larger leaves), linear, 10-30 × 2-3 mm, strigose to scabrous. Peduncles to 11 mm. Involucres narrowly campanulate to cylindric, 5-8 × 5-8 mm. Phyllaries oblong, often becoming scarious, glabrous or appressed-hairy distally, apices obtuse, erose-ciliate (red-tipped). Paleae yellowish (often red-tipped), apices obtuse, erose. Ray florets 3-6; corollas bright yellow, laminae ovate to orbiculate, mostly 10-18 mm. Disc florets 18-24; corollas red or green, to 10 mm, lobes 1 mm. Cypselae 4-5 mm, 3-angled (ray) or angular or compressed (disc), ribbed, scabrellous; pappi 0 or of (1-)2(-4) unequal awns. 2n = 42.
FNA 2006, Martin and Hutchins 1980, Heil et al. 2013
Duration: Perennial Nativity: Native Lifeform: Subshrub General: Rounded or flat-topped perennial herbs, sometimes slightly woody, 8-22 cm tall, from a branched woody caudex; stems diffusely branched and roughly short-hairy. Leaves: Opposite, sessile, and crowded along the stems; blades linear, 1-3 cm long by 2-3 mm wide, usually 3-nerved, at least near the leaf base, rarely 1-nerved; surfaces covered with rough, short stiff hairs. Flowers: Flower heads showy and radiate, yellow with red-orange centers, on the tips of leafy branches; involucres campanulate to cylindric, 5-8 mm high; the bracts (phyllaries) oblong, thin and papery (scarious), in 3-4 graduated series, straw colored to yellow, often with red-tinted tips; ray florets 3-6 per flower head, the laminae (ray petals) bright yellow, ovate to orbiculate, 1-2 cm long; disc florets 18-24 per flower head, red to orange or occasionally green. Fruits: Achenes 4-5 mm long, ribbed and scabrellous; topped with pappus of 2 unequal awns (sometimes absent). Ecology: Found on dry slopes and flats, sometimes on calcareous soils, from 3,000-7,500 ft (914-2286 m); flowers June-September. Distribution: AZ, NM, CO, OK, s KA, TX; south to c MEX. Notes: An attractive, low-growing, mound-forming, perennial herb to subshrub; distinguished by its stiff-hairy linear leaves with 3 veins (1-veined in Z. acerosa); the few (3-6) showy, yellow ray flowers (white in Z. acerosa); and few deep-orange disc flowers. The ray petals droop a bit, are persistent, and become papery with age, making this species strongly resemble a paperflower (Psilostrophe spp). However Psilostrophe spp have yellow disc flowers and this species has red-orange disc flowers. Ethnobotany: Taken to treat kidney trouble, nose and throat trouble, and stomachaches; also used as a ceremonial emetic, applied to bruises, used as an eyewash, and made into both yellow and red dye. Etymology: Zinnia is named for Johan G. Zinn (1729-1759) a German botanist; grandiflora mean large-flowered. Synonyms: Crassina grandiflora Editor: SBuckley 2010, FSCoburn 2015, AHazelton 2017