Rinorea betancurii Hoyos-Gómez, 2024

Hoyos-Gómez, Saúl E., Callejas Posada, Ricardo & Wahlert, Gregory A., 2024, Seven new species of Rinorea (Violaceae) from the Neotropics, PhytoKeys 242, pp. 241-271 : 241-271

7. Rinorea betancurii Hoyos-Gómez sp. nov.

Type.

Colombia. Dept. Caquetá: Mpio. de Solano, región de Araracuara , sector Chiribiquete , camino a Tepuí , 0 ° 12 ' 16 " S, 72 ° 29 ' 14 " W, 170 m elev., 10 Dec 2010, F. Castro 10919 (holotype: COAH [acc. 78339 ]!; isotype: NY [barcode 02691382 ]!) .

Description.

Rinorea betancurii is similar to R. macrocarpa by the elliptic lamina lacking domatia, lamina base symmetrical and capsule symmetrical with apex acuminate, but it differs by the abaxial lamina surface pubescent (vs. abaxial lamina surface glabrous in R. macrocarpa ), lamina base obtuse (vs. lamina base cuneate), fruit smaller 2.5–3 cm long (vs. fruit larger, 3–5.7 cm) and valves containing two pubescent seeds (vs. valves containing three glabrous seeds).

Treelets 1.5–5 m tall, branchlets with puberulent erect ferruginous trichomes 0.1–0.2 mm long, glabrescent. Leaves opposite, petiolate; petiole 2–4 mm long, pubescent with erect ferruginous trichomes 0.2 mm long; stipules deciduous, free, lanceolate, 2.3–3 × 1–1.1 mm, herbaceous, pubescent with appressed ferruginous trichomes 0.2 mm long, lamina elliptic, 6.3–14.4 × 2.6–7 cm, adaxially glabrous, abaxially pubescent with erect ferruginous trichomes 0.2–0.4 mm long, semi-craspedodromous, with 5–7 major secondary vein pairs, secondary veins with spacing between them decreasing proximally, symmetrical, base obtuse, margin entire to subcrenate, apex acute, acumen 8–14 mm long, mucronate, domatia absent. Flowers unknown. Fruit a symmetrical, subligneous capsule dehiscent along three sutures, ellipsoid, 2.5–3 × 0.5–0.6 cm, apex acuminate, pubescent with curved golden trichomes 0.3–0.4 mm long, green in vivo, brown when dry. Seeds two per valve, globose, 7–8 mm diam., pubescent with spreading trichomes 0.1–0.2 mm long, with maculae, seeds brown when dry. (Fig. 11 )

Distribution and habitat.

Rinorea betancurii occurs in Brazil, Colombia and Venezuela, an area that corresponds to the Biogeographic Provinces of Imerí and Pantepui in the Boreal Brazilian Dominion (sensu Morrone (2014)). The species grows in lowland tropical rainforest at elevations of 60– 170 m. Rinorea betancurii has been recorded as growing in sandy soils near rivers and on slopes and hills. (Fig. 4 )

Etymology.

Rinorea betancurii honours Julio Betancur, Colombian botanist and curator at the National Herbarium in Bogotá. Dr. Betancur has inspired a new generation of students to pursue a career in botany and has made many contributions to the taxonomic knowledge of the Bromeliaceae , Heliconiaceae and the flora of Colombia.

Phenology.

Fruiting specimens were collected in February through May and in September, November and December.

Conservation status.

Rinorea betancurii has a geographic range in the form of an estimated EOO of 511,480 km 2 and an AOO of 36 km 2. The species is known from eight localities, none of which appear to be in protected areas. Based on satellite imagery from Google Earth, the locations in Colombia and Brazil appear to be heavily impacted by deforestation, while the four Venezuelan locations are in remote and vast primary forests with large buffers from disturbed areas. Even though we project continuing decline in the extent and quality of habitat for the Colombian and Brazilian locations, the undisturbed forests in southern Venezuela appear to be safe from large-scale disturbance for the foreseeable future. Nevertheless, it appears unlikely that the species will qualify for a threatened status in the near future and is assigned a preliminary status of Least Concern ( LC).

Notes.

Rinorea betancurii occurs with R. pubiflora var. pubiflora , but it can be separated by the valves that contain two seeds (vs. valves that contain three seeds in R. pubiflora var. pubiflora ).

Additional specimens examined.

Colombia. Dept. Caquetá: cabeceras del río Masay, desembocadura del río San Jorge al río Cuñaré , 1–6 Mar 1980 (fr), M. Pabón 946 ( COL) . Dept. Meta: Mpio. Puerto López, vereda el Tigre, finca Pista , orilla del canal, 8 Feb 2008 (fr), F. Castro 4760 ( UBDC) . Dept. Vaupés: Mpio Taraira, comunidad Jotabeyá , 0 ° 35 ' S, 70 ° 11 ' W, 150–250 m elev., 27 Mar 2009 (fr), J. Betancur et al. 13854 ( COAH, COL, HUA) . Venezuela. Bolivar State: Mpio. Foráneo Aripao, margen derecha del caño Minchaquene ( Hormiga ), tributario del Alto Caura , entre Araguaña y Campamento , 4 ° 45 ' N, 64 ° 12 ' W, 2 May 1988 – 5 May 1988 (fr), G. Aymard 6810 ( MO, NY, U) . Amazonas State: Mpio. Atabapo, río Cunucunuma, raudal Mapaco , 3 ° 37 ' N, 65 ° 51 ' W, Apr 1990 (fr), W. R. Anderson 13343 ( F, MICH) ; close to cerro Neblina base camp on río Mawarinuma , 0 ° 50 ' N, 66 ° 10 ' W, 6 Feb 1984 (fr), R. L. Liesner 15689 ( BHO, MO, U, VEN) ; Cerro Yapacana , 3 ° 45 ' N, 66 ° 45 ' W, 125–400 m elev., 3 May 1970 (fr), J. Steyermark et al. 113015 ( COL) . Brazil. Amazonas State: Mpio. Barcelos, base cerro Aracá , 0 ° 42 ' N, 63 ° 22 ' W, 14 Jul 1985 (fr), I. Cordeiro 193 ( INPA, NY) .

Figures

Figure 4. Distribution of R. melanodonta (triangles), R. macrocarpa (asterisks), R. betancurii (pentagons), Rinorea aymardii (squares).

Figure 11. Rinorea betancurii Hoyos-Gómez A habit B detail of leaf, abaxial surface C leaf architecture D fruit and detail of pubescence E detail of fruit showing two seeds per valve F seed. (A – F: R. L. Liesner 15689 [MO]).