Coarsely herbaceous sparingly branched vines; stems yellowish to brown, terete, striate, glabrate to minutely puberulous, the larger stems usually fistulose. Leaves opposite; blades ovate, to 18 cm long and 11 cm wide, the base rounded to slightly cordate, the margins entire and slightly recurved, the apex abruptly shortly caudate-acuminate, the upper surface glabrate, the lower surface short-puberulous, without evident glandular-punctations, 2-3 pairs of prominent secondary veins arching outward and upward from basal fifth of the blade, the tertiary veins regularly transverse, prominent beneath; petioles slender, 1-3 cm long. Inflorescence a panicle with elongate strictly spicate branches. Heads 5-6 mm high; subinvolucral bract ovate, acute, ca. 1.5 mm long, minutely puberulous; involucral bracts oblong with rounded tips, 3.0-3.5 mm long, ca. 0.8 mm wide, the outer pair minutely puberulous; corolla white, fragrant, 2.5-3.0 mm long, the tube narrow, 1.0-1.5 mm long, the limb narrowly campanulate with prominent undulations on the lower inside surface, the lobes 1-2 times as long as wide with a few glands outside, the corolla cells oblong, 15-25 M wide, mostly with sinuous walls; anther appendages firm, ovate, ca. 1?/-times as long as wide; style base somewhat thickened, glabrous, the style appendages with short papillae. Achenes with 5 ribs, 1.5-2.0 mm long, glabrous; pappus of 35-40 slender bristles in 1 series, the apices slightly to distinctly thickened.
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