Sparingly branched herbaceous vines; stems greenish to brownish, terete, distinctly striate, often fistulose. Leaves opposite; blades ovate, 5-10 cm long and 2.0-4.5 cm wide, the base rounded, the margins entire to subentire, the apex caudate-acuminate, the surface glabrous without glandular punctations, 2 pairs of strongly ascending secondary veins in the basal fifth of the blade, the finer vein reticulations with prominent, included, branched vein endings; petioles slender, 1-2 cm long. Inflorescence a panicle with paniculate branches, the branches puberulous; ultimate branches 0-1 mm long. Heads 7-8 mm high; subinvolucral bract ovate-lanceolate, 1.5-2.0 mm long, glabrous outside; involucral bracts narrowly oblong with rounded tips, ca. 5 mmn long, ca. 1 mm wide, glabrous on the outer surface except on the somewhat pitted swollen base; corolla whitish, ca. 3 mm long, the tube 1.2-1.5 mm long, the limb narrowly campanulate with short lobes about as long as wide, few glands or hairs outside, usually a few hairs on the tube, the corolla cells quadrate to short-oblong, ca. 25 JL wide; anther appendages firm, rounded, about as long as wide; style base thickened, glabrous, the style appendages with short papillae. Achenes 5-ribbed, ca. 4 mm long, glabrous or with numerous small glands; pappus of 35-40 slender bristles in 1 series, tips distinctly enlarged.
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