Annuals or perennials, 2-50+ cm (perennials with ± branched, woody caudices). Stems 1-60, erect or ± decumbent, unbranched or sparingly branched distally. Leaves all basal, or basal-proximal, or basal and cauline; alternate; petiolate or sessile; blades (usually with distinct midribs) mostly oblanceolate to linear or filiform, sometimes lobed, ultimate margins usually entire, sometimes toothed, faces glabrous or ± hairy, eglandular or ± gland-dotted. Heads radiate or discoid, borne singly or in paniculiform to corymbiform or fastigiate arrays. Involucres hemispheric to campanulate 6-20 mm diam. Phyllaries 11-60+ in 3 series (mostly spreading to erect in fruit, distinct, herbaceous; outer with or without scarious margins, abaxial faces ± hairy; mid usually same number as, alternating with, and similar to outer, almost always with ± scarious margins; inner narrower than others, margins scarious). Receptacles hemispheric to conic, shallowly pitted or smooth, epaleate. Ray florets 0 or 7-27, pistillate, fertile; corollas (usually marcescent) yellow (laminae fan-shaped to oblanceolate, usually 3-lobed). Disc florets 20-250+, bisexual, fertile; corollas yellow proximally, yellow or purplish distally, tubes shorter than cylindric to cylindro-campanulate throats, lobes 5, ± deltate. Cypselae ± obpyramidal, moderately to densely hairy; pappi persistent, of 4-8 usually aristate, scales. x = 15.

Here, strigoso-canescent refers to often silvery induments (hairs tightly appressed, relatively short, 1-1.5 mm) of Tetraneuris argentea and T. acaulis var. acaulis. Such induments contrast with lanuginose or sericeous induments (hairs spreading, ca 1.5-3 mm) in other taxa, including T. ivesiana and the other three varieties of T. acaulis.