Annual or perennial herbs or small shrubs. Leaves opposite (rarely in whorls of 3), becoming alternate above, sessile or petiolate, simple (lanceolate to linear) or pinnate, entire or toothed at apex. Inflorescence of heads in terminal congested panicles or corymbs. Capitula homogamous, cylindrical; involucral bracts herbaceous, 5, equal to subequal, in 1 series, ± imbricate, free to base; receptacle flat, naked (lacking paleae). Disc florets bisexual; corolla tubular, 5-toothed, usually hairy, white, pink or lavender to purple. Achenes cylindrical to clavate, 4-or 5-angular. Pappus variable: a jagged cup, fused scales, and/or bristles.
The genus is noted for the shrub Stevia rebaudiana (Bertoni) Bertoni, Stevia, Sweetleaf or Sugar leaf, native to Paraguay and Brazil, which contains the glycosides stevioside, rebaudioside-A and-D and other compounds which are many times sweeter than sucrose. The leaves are used to produce a sugar substitute, particularly in China, Japan and India, and it has been proposed as a new crop for Australia (T. Lester, Stevia rebaudiana (Sweet Honey Leaf). Austral New Crops Newslett. 11, article 16.1 (1999); N.W. Megeji et al., Introducing Stevia rebaudiana, a natural zero-calorie sweetener, Curr. Sci. 88: 801–804 (2005)).
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