Plants annual or short-lived perennial; taproots narrow, enlarged when perennial, semiwoody. Stems several (rarely 1), erect or ascending, sometimes procumbent, usually much-branched from base, slender, 1–5(–10) dm, densely or sparsely villous-tomentose with grayish white hairs. Leaves predominant on proximal 1/3 of plant, often basal, sessile; blade linear to lanceolate or lance-elliptic, largest leaves 1.6–9(–13.5) × 0.2–0.9(–1.2) cm, base acuminate or attenuate, apex acute to acuminate, canescent or sericeous adaxially, sericeous-tomentose with white or gray hairs abaxially. Spikes sparsely branched, flowers arranged in 3-ranked spiral; bracteoles stramineous or blackish, glabrous. Flowers 2.4–3.8 mm; perianth lobes oblong-linear, apex acute or acutish, pubescence grayish; filament lobes stramineous or blackish, blunt. Utricles 2.5–5 × 2.7–4 mm, apex slightly oblique, with irregularly and deeply cut (“spiny”) lateral wings, both surfaces of perianth with distinct spines or tubercles. 2n = 54.
