Rinorea bicornuta Hekking

9.Rinorea bicornutaHekking. Phytologia 43: 474. 1979. Type. Brazil • Amazonas: Tocantins, Solimões, 1927, W. A. Ducke 21353 (holotype: RB [barcode RB 00560922]!; isotype: RB [barcode RB 00544454]!). Description. Tree 5–12 m tall, branchlets densely strigose with ferruginous erect trichomes 0.2–0.3 mm long, lenticels 0.5–1 mm long. Leaves alternate, petiolate, petioles 6–9 mm long, pilose with golden appressed trichomes 0.3–0.6 mm long, glabrescent; stipules deciduous, free, triangular, 3–4 × 1–1.7 mm, veined, costa pilose, margin ciliate, apex acuminate, mucronulate; lamina elliptic, 10–25 × 5–12 cm, foliaceous, glabrous on both sides, costa sparsely pilose on both sides with golden appressed trichomes 0.1–0.3 mm long, with 8 to 11 pairs of major secondary vein, tertiary venation brochidodromous, base symmetrical, cuneate; margin subentire to subcrenate, apex acuminate, acumen 0.5–1 cm long, mucronulate, domatia absent. Inflorescence axillary and terminal, thyrsoid, solitary or in 2 to 3 fascicles, 7–15 cm long, rachis green when fresh, brown when dry, cymules with 1 to 5 flowers; common peduncle 2.5–5 mm long, pubescent with dispersed pilose golden trichomes 0.1–0.2 mm long; pedicels 2–4 mm long, articulated near the base, pubescent with pilose golden trichomes 0.1–0.2 mm long; bracts deciduous, lanceolate, 1–1.5 × 1–1.5 mm, costa pubescent with golden pilose trichomes 0.1–0.2 mm long, margin ciliate, mucronulate; bracteoles deciduous, ovate, 0.8–1.1 × 0.4–0.6 mm, subopposite, costa pubescent with golden pilose trichomes 0.1–0.2 mm long, margin ciliate, apex acuminate, mucronulate. Flowers subzygomorphic, 3.5–4 × 3.5–4 mm, flower buds conical; sepals ovate, 1.5–2 × 0.9–1.1 mm, pubescent near the base and along the costa with pilose golden trichomes 0.1–0.2 mm long, margin ciliate, apex subobtuse, mucronate, with 1–3 longitudinal veins; petals cream-colored, ovate, 3–4 × 0.8–1.5 mm, pubescent along the costa with dispersed pilose golden trichomes 0.1–0.2 mm long, margin sparsely ciliate, apex obtuse, cream when fresh, brown when dry; stamens 2.5–3 × 1.0– 1.2 mm, filaments and dorsal glands adnate to form a staminal tube 0.2 mm tall, carnose, glabrous, anthers 0.8–1 × 0.4–0.5 mm, subsessile, ovoid, with two apical cusps 0.3–0.5 × 0.1–0.2 mm; connective ca. 0.75 × ca. 0.25 mm, pubescent with dispersed pilose trichomes 0.1–0.2 mm long, dorsal anther connective scale lanceolate, 2–2.5 × 0.7–0.9 mm, scarious, margin entire, apex acuminate, brown when dry; ovary 0.8–1 mm, ovate, pubescent apically with pilose golden trichomes 0.2–0.3 mm long; style 2–2.5 mm long, erect, glabrous, stigma apiculate. Fruit an asymmetrical capsule dehiscent along three sutures, ellipsoid, 5–12 mm × 4–8 mm, pubescent with dimorphic golden trichomes, smaller trichomes 0.1 mm long, erect, larger trichomes 0.2–0.4 mm long, appressed; valves unequal, large valve 10–12 × 5–6 mm, smaller valves 6–7 × 4–5 mm, with persistent floral parts at the base. Seeds one per valve, ovoid, 4–5 mm diam., glabrous, shiny brown without maculae, with a conspicuous lateral hilum (Fig. 9). Distribution and habitat. Rinorea bicornuta is an endemic species near the border region of Colombia and Brazil, an area corresponding to the Imerí biogeographical province (sensu Morrone 2014; Fig. 8). It occurs in primary lowland wet forests between 50 and 200 m elevation. Phenology. The species was recorded in flower in February and November and in fruit in February. Notes. Rinorea bicornuta was described by Hekking (1979) from a single flowering specimen. Over the course of revising the genus from Colombia, a second fruiting herbarium specimen from Vaupés Department was observed and allowed us to provide and updated description here. Additional specimens examined. Colombia. Vaupés: • Taraira, Estación Biológica Mosiro Itajura (Caparú), 01°04'21.8"S, 69°31'2.9"W, 200 m, 20 Feb 2004 (fl, fr), L. Clavijo 404 (COAH, COL, HUA, UBDC).