Rogersonanthus quelchii

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Rogersonanthus quelchii


Small tree or shrub, up to 5 m high, branched. Stems and branches up to 1 cm in diam., quadrangular, slightly winged; internodes 0.5-2 cm long. Leaves shortly petiolate, arranged along stem; petiole 0.2-0.6 cm long; blade coriaceous, broadly elliptic-oblanceolate to obovate, 1.9-5(-7) x 1.4-4 cm, margin slightly revolute, apex obtuse to bluntly acute, base acute. Inflorescence 1-6-flowered; bracts awl-shaped, 2-3 mm long; pedicel 5-15 mm long. Flowers erect to horizontal; calyx green, 6-11 x 6-10 mm, lobes with paler greenish glands on dorsal side, elliptic, 4-8 x 3-6 mm, margin hyaline, apex obtuse to bluntly acute; corolla green to greenish yellow, funnel-shaped, 21-44 mm long, 16-20 mm wide at mouth, lobes elliptic, 7-11 x 9-11 mm, apex obtuse; stamens not extending beyond corolla lobes, filaments 9-13 mm long, straight, anthers yellow(?), linear-elliptic, 6-8 mm long, straight first, then strongly recurved after anthesis; pollen exine a differentiated reticulum; pistil 25-34 mm long, ovary 5-7 x 4-5 mm, style 20-22 mm long, stigma lobe oblong, 3 x 1 mm. Fruit erect to nodding, green, ovoid, 11-15 x 8-10 mm; seeds brown, 1 mm in diam.


Guyana present, Guyana-Brazil-Venezuelan-frontier present, summits and slopes of Roraima mountain chain from Roraima to Ilu-tepui present
Guyana-Brazil-Venezuelan-frontier, summits and slopes of Roraima mountain chain from Roraima to Ilu-tepui; 17 collections studied, of which 4 from Guyana (GU: 4).


Flowering .


This species has previously been included in Irlbachia (Maas, 1985), but it is most closely related to the green and white-flowered Chelonanthus, Helia, and Adenolisianthus (Struwe et al., 2009).