Herbs perennial, 50-100 cm tall. Stems stout, ribbed, glabrous. Basal and lower stem leaves oblong-elliptic, 15-25 × 7-9 cm, abaxially gray-green, densely pubescent, adaxially green and glabrous, base attenuate, apex acuminate; middle and upper stem leaves short petiolate or sessile, oblong to lanceolate, 10-15 × 3-5 cm. Inflorescences terminal or axillary, paniculate, ebracteate. Pedicel 1.5-3 mm, to 1 cm after anthesis, recurved, densely white pilose. Calyx 2.5-4 mm, appressed pubescent outside; lobes oblong-linear. Corolla greenish yellow, 4.5-5.5 mm, base 1-1.5 mm wide; throat appendages trapeziform, ca. 1.5 × 1 mm; limb 5-6 mm wide; lobes orbicular. Stamens inserted on middle of corolla tube; anthers oblong, ca. as long as appendages. Style ca. 1.5 mm. Nutlets ovoid to rhombic-ovoid, 5-7 × 4.5-5.5 mm; prickles dense, anchorlike, abaxially concave, obscurely keeled or without keels along center line; attachment scar above middle adaxially, ovate-oblong. Fl. May-Jun, fr. Jul-Aug.
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