Rinorea pabongonzaleziorum Hoyos-Gómez, 2025

Hoyos-Gómez, Saúl E., Ballard Jr., Harvey E., Callejas Posada, Ricardo & Wahlert, Gregory A., 2025, Taxonomic clarifications, a new combination, and three new species of Neotropical Rinorea (Violaceae), PhytoKeys 256, pp. 151-174 : 151-174

3. Rinorea pabongonzaleziorum Hoyos-Gómez sp. nov.

Type.

Colombia. Dept. Vaupés: • Mpio. Mitú, above Mitú, bank of río Vaupés , 200 m, 24 Mar 1970, D. D. Soejarto 2315 (holotype: HUA [acc. no. 3197; barcode HUA – 0019764]!; isotype: F [acc. no. 1835143]!) .

Diagnosis.

Rinorea pabongonzaleziorum resembles R. macrocarpa (Mart. ex Eichler) Kuntze by the opposite leaves lacking domatia, racemose inflorescence, praemorse margin of the dorsal anther connective scale, and filaments connate at the base forming a staminal tube, but it differs by the obovate lamina (vs. elliptic lamina in R. macrocarpa ), 4 to 6 major secondary vein pairs (vs. 7 to 9), two glabrous seeds per valve (vs. three), smaller fruits 2.5–3.2 × 2–2.5 cm (vs. 3.5–5.8 × 2.5–3 cm), and smaller seeds 5–7 mm diam. (vs. 7.5–9 mm diam.).

Description.

Treelets 3–5 m tall, terminal branchlets pubescent with appressed ferruginous trichomes 0.1–0.3 mm long, callose lenticels 0.5–0.6 mm long, brownish when dry. Leaves opposite, petiolate; petiole 3–6.5 mm, pubescent with appressed ferruginous trichomes 0.1–0.3 mm long; stipules deciduous, free, lanceolate, 2–4 × 1–1.5 mm long, densely pubescent with appressed golden trichomes, 0.2–0.3 mm long; lamina obovate, 6–15 × 4–8 cm, foliaceous, adaxially glabrous, abaxially pubescent on midvein, secondary and tertiary veins with appressed scattered golden trichomes 0.3–0.5 mm long, veins pinnate, semicraspedodromous, with 4 to 6 pairs of major secondary vein, secondary veins with unequal spacing between them, percurrent, base symmetrical, cuneate, margin subcrenate to subentire, apex acuminate, acumen 1–1.8 cm, mucronulate, leaf domatia absent. Inflorescence terminal, racemose, solitary, 3–4 × 0.8–1.5 cm, central axis brown, densely pubescent with erect ferruginous trichomes 0.2–0.3 mm long; pedicels 0.5–0.9 mm, pubescent with erect ferruginous trichomes 0.2–0.3 mm long, articulated at the base; bracts persistent, triangular, 1–1.2 × 1–1.2 mm long, costa pubescent with appressed golden ferruginous trichomes 0.2–0.3 mm long, margin ciliolate, mucronulate; bracteoles persistent, triangular, 0.5–0.6 × 0.5–0.6 mm, opposite, costate, pubescent with appressed ferruginous trichomes 0.2–0.3 mm long, margin ciliolate, apex acuminate, mucronulate. Flowers 3–4 × 3–4 mm, subzygomorphic; sepals triangular, 1–1.2 × 0.8–0.9 mm, densely pubescent with appressed golden trichomes 0.2–0.3 mm long, margin ciliolate, apex apiculate; petals white, lanceolate, 3–3.5 × 1.2–1.5 mm, costa pubescent with scattered ferruginous trichomes 0.3–0.4 mm long, glabrescent, margin entire, apex reflexed; stamens 2.3–2.6 × 1–1.3 mm, filaments connate at the base forming a glabrous staminal tube with glands covering the filament, tube 0.5–0.6 mm tall, anthers elliptic to ovoid, 0.8–0.9 mm, glabrous, dorsal anther connective scale lanceolate, 1.4–1.7 × 1.3–1.5 mm, margin strongly fimbriate, cream-colored; ovary pyriform, 2–2.2 × 1.3–1.5 mm, densely pubescent with appressed golden trichomes 0.3–0.5 mm long; style filiform, erect, 0.4–0.6 mm long, glabrous, stigma acute. Fruit a symmetrical subligneous capsule dehiscent along three sutures, ellipsoid, 2.5–3.2 × 2–2.5 cm, apex acuminate, pubescent with golden uncinate trichomes 0.1–0.2 mm long. Seeds two per valve, globose, 5–7 (8) mm diam., glabrous, with maculae, brown when dry (Fig. 5 ).

Distribution and ecology.

Rinorea pabongonzaleziorum is endemic to the border region between Colombia and Venezuela, in the Imerí and Pantepui biogeographical provinces (sensu Morrone 2014; Fig. 2 ). It occurs in primary and secondary tropical wet forest, often on hill slopes, at elevations from 140 to 300 m.

Etymology.

Rinorea pabongonzaleziorum is named in honor of Professors Dr. Natalia Pabón M. and Dr. Favio González G., who have made significant contributions to the knowledge of the flora of Colombia. Professor Natalia Pabon M. is a specialist in floral evolution and development at Universidad de Antioquia, Medellín, and Professor Favio González G., at the Universidad Nacional de Colombia, Bogotá, specialized in the taxonomy of South American Aristolochiaceae and Campanulaceae .

Phenology.

The species was recorded in flower in February and March and September through December. It was in fruit in February, March, and December.

Conservation status.

Rinorea pabongonzaleziorum is known from 14 collections representing nine occurrences. It has a geographic range in the form of an estimated EOO of 211,657 km 2 and an AOO of 32 km 2. The species occurs in Serranía La Neblina National Park in Venezuela, but across the rest of its range, it is subject to deforestation for timber extraction, agriculture, and grazing. We project that ongoing deforestation will lead to continuing decline in the area, extent and / or quality of habitat of the species. With regard to the most serious plausible threat of deforestation, the nine occurrences represent six locations. Therefore, R. pabongonzaleziorum is preliminarily assessed as “ Vulnerable ” [VU B 2 ab (iii)] in accordance with the IUCN Red List Categories and Criteria ( IUCN 2024).

Additional specimens examined.

Colombia. Dept. Vaupés: • Mpio. Taraira, comunidad Jotabeyá, caño Jotabeyá, mas adentro del río Apaporis, varador “ Chorro de Yarumo, ” 0°35'S, 70°11'W, 150–250 m, 27 Mar 2009 (fr), J. C. Betancur B. 13854 ( COAH, COL, HUA) ; • Mpio. Mitú, km 11.2 carretera Mitú – Montfort , Sep 1993 (fl), X. Martínez et al. 1322 ( HUA) ; • Mpio. Mitú, Caño Cucura , 01°09'39"N, 70°08'49"W, 147 m, 7 Dec 2021 (fl, fr), S. E. Hoyos-Gómez 4850 ( HUA, JAUM, COAH, MO, US, NY) ; • Carretera Mitú-Tayazu , 01°05'09"N, 70°03'22"W, 180 m, 22 Ago 2024 (fr), S. E. Hoyos-Gómez 5792 ( HUA, JAUM, COAH) ; • Río Guainía, Puerto Colombia (opposite Venezuelan town of Maroa) and vicinity , 249–254 m, 31 Oct – 2 Nov 1952 (fl), R. E. Schultes 17932 ( US) ; • ibid., R. E. Schultes 17933 ( US, GH) . Venezuela. Amazonas State: • Dept. Río Negro, Neblina Base Camp, Río Mawarinuma , 0°50'N, 66°10'W, 140 m, 25 Nov 1984 (fl), B. B. Boom 5132 ( MO, NY, GH) ; • ibid., 2 Feb 1984 (fl, fr), B. B. Boom 5536 ( INPA, K, MO, US) ; • Río Negro, 1.5 km south of Cerro de La Neblina Base Camp, which is on Río Mawarinuma , 0°50'N, 66°10'W, 140 m, 12 Mar 1984 (fl, fr), R. L. Liesner 16554 ( BHO, MO, VEN) ; • ibid., 27 Nov 1984 (fr), R. L. Liesner 17352 (F, MO, US) ; • Cerro Neblina base camp along Río Mawarinuma , ca. 0°50'N, 66°10'W; 140 m, 2 Dec 1984 (fl), T. B. Croat 59562 (F, MO, NY, US) ; • Dpto. Atures, 125 km de la boca (delta) del Guayapo en Sipapo , 04°22'N, 67°06'W, 130 m, May 1989 (fr), E. Foldats et al. 9187 ( MO, NY) ; • Mpio. Foraneo Aripao, margen derecha del caño Minchaquene (Hormiga), tributario del Alto Caura, entre Araguaña y Campamento , 7°20'N, 65°10'W, 300 m, 2–5 May 1988 (fr), G. A. Aymard C. et al. 6810 ( MO) .

Figures

Figure 2. Distribution of Rinorea cardenasii (stars) and R. pabongonzalezii (triangles).

Figure 5. Rinorea pabongonzaleziorum Hoyos-Gómez A habit B detail of pubescence on young twig C detail of lenticels on young twig D inflorescence E flower F sepals abaxial surface G petals, detail of abaxial and adaxial surface H stamens, detail of abaxial and adaxial surface I androecium, detail of fused stamens forming a staminal tube J gynoecium K fruit L detail of open fruit showing two seeds per valve M seed (A – M: D. D. Soejarto 2315 [HUA]).