In 1953* we recognized six species in Stenopadus proper (Eustenopadus Blake), all endemic to the Guayana Highland. Now, as a result of further exploration, eight additional species have been collected (two of them to be described in the succeeding paper) in Venezuelan Guayana, and one, S. colombianus Cuatr. & Steyerm., has been described from Colombian Guayana.
Heads massive, terminal, solitary (in three species sometimes 2-4), homogamous, multiflowered [(15) 40-100]; receptacle glabrous, alveolate, strongly or sometimes not at all paleaceous; corolla actinomorphic, carnose, essentially infundibuliform and differentiated into a cylindric tube, an expanded limb, and tightly coiled, linear-lanceolate lobes, the tubular portion much exceeding the lobes, characteristically 3 (sometimes only 2) distinct veins extending from the base of the corollas into the lobes; anthers caudate-sagittate, the adjacent tails connate; filaments attached either in the sinus of the lobes, at the union of the tube and the limb, or below this union; pollen grains yellowish, tricolpate, the furrows long-pointed; grains prolate to subprolate (prolate-spheroidal in S. campestris), spinulose or psilate; polar axis 55-65 fi', achenes prismatic, basically 10-nerved, glabrous; annulus mostly lacking; corona cylindric; pappussetae mostly subpaleaceous, flattened and connate into a ring at the base. Trees.
TYPE species: Stenopadus talaumifolius Blake.