Herpetacanthus rotundatus

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Herpetacanthus rotundatus


Shrub or subshrub, 1-1.5 m tall. Stem subquadrangular, branching, younger stem puberulous, older stem glabrate. Petiole 0.5-2 cm long, puberulous; blade elliptic to narrowly ovate, 6-14 x 4-6.5 cm, glabrous or subglabrous on both upper and lower surface, apex acute, base attenuate and decurrent on petiole, margin entire to shallowly crenulate; secondary veins 8-10 pairs prominent; leaves subtending inflorescence usually reduced, frequently more ovate and basally rounded than cauline leaves. Inflorescence terminating main and lateral branches, spikes solitary or in groups of 2 or 3, 3-4 cm long; peduncle 0.5-1 cm long; rachis zigzag, glabrous to minutely pubescent; bracts ovate-orbicular, 12-13 x 8-10 mm, apically obtuse or subobtuse and minutely mucronulate, 3-4-veined, pale green, usually somewhat oblique, glabrous, shortly ciliate; bracteoles narrowly triangular, 4 x 0.6 mm, glabrous. Flowers alternate, in pairs or single between paired bracts; calyx 3.5-4 mm long, glabrous, posterior lobe 0.6 mm wide, anterior and lateral pairs 0.4 mm wide; corolla white or pale violet, 15-16 mm long, glabrous, tube 11-12 mm long, cylindrical basal part 7 mm long, campanulate upper part 6-7 mm wide at throat, upper lip erect, narrowly ovate, 3.8 mm long, middle lobe of lower lip ovate, 2 x 1.5 mm, apically obtuse, lateral lobes narrowly ovate, 2 x 1 mm; stamens inserted in middle of campanulate part of corolla tube, filaments 22 and 44 mm long respectively, anther thecae 1.1 mm long, 1-thecous anthers crowned with a hairlike appendage; pollen 47 μm in diameter; ovary glabrous, 1 mm high, style puberulous, 13 mm long, stigma lobes 0.5 mm long. Capsule 10 mm long, 3 mm wide, stipe 4 mm long, body ellipsoid, glabrous to sparingly puberulous; seeds flattened, reddish-brown, irregularly orbicular, 2 x 1-1.5 mm.


Amazonian Ecuador present, French Guiana present, Guianas present, Southern America: Peru (Peru present), Suriname present
Amazonian Ecuador, Peru and Brazil and in Suriname and French Guiana; 11 collections studied from the Guianas (SU: 4; FG: 7).


Flowers reported , fruits reported .