6. Stevia serrata Cavanilles, Icon. 4: 33, plate 355. 1797.
Stevia serrata var. haplopappa B. L. Robinson; S. serrata var. ivifolia (Willdenow) B. L. Robinson
Perennials, 40–100 cm. Leaves mostly alternate (at least not regularly opposite, crowded, with axillary clusters of smaller leaves); petioles 0; blades (3-nerved) narrowly lanceolate to lance-linear, 1.5–4 cm, margins serrulate. Heads borne in ± congested, compact clusters. Peduncles 0 or 1–4 mm, sessile-glandular, villous-puberulent. Involucres 5–6(–7) mm. Phyllaries sessile-glandular, sparsely villosulous, apices acute to acuminate. Corollas white or pink, lobes sparsely sessile-glandular, finely villous-hirsute. Pappi usually ± equaling corollas, sometimes coroniform or 0. 2n = (22–)34(–54) univalents, less often 17 pairs.
Flowering (Jul–)Aug–Oct. Roadsides, disturbed sites, oak-grasslands, oak-pine grasslands, and oak, mixed conifer-oak, mixed pine, ponderosa pine-Douglas fir, pine-fir-aspen, spruce-Douglas fir, and fir-hemlock woodlands; 1700–2700 m; Ariz., N.Mex., Tex.; Mexico.
Some collections of Stevia serrata from Cochise and Graham counties, Arizona, were annotated by J. L. Grashoff as "S. serrata > plummerae"; in leaf arrange-ment and morphology (venation, margin, and shape), they appear to be similar to typical S. serrata from the same area.