Rinorea idarragae 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

2. Rinorea idarragae Hoyos-Gómez sp. nov.

Type.

Costa Rica • Prov. Puntarenas: Reserva Forestal Golfo Dulce, Península de Osa, Rincón, Banegas, camino a Rancho Quemado en la primera cuesta , 08°40'34"N, 83°32'11"W, 192 m, 20 Jul 2010, S. E. Hoyos-Gómez & R. A. Aguilar Fernández 1110 (holotype: MO [acc. no. 6335352; barcode MO- 2326294]!; isotypes: MEDEL [acc. no. 56951]!; MO [acc. no. 6335353; barcode MO- 2326291]!; MO [acc. no. 6603524; barcode MO- 2679512]!; HUA [acc. no. 179370; barcode HUA – 001977]!; HUA [acc. no. 179369; barcode HUA – 0019778]!; JAUM [acc. no. 058851]!; JAUM [acc. no. 058843]!; CR [cat. no. 4238055]!; NY [barcode 02841133]!) .

Diagnosis.

Rinorea idarragae resembles R. paniculata (Mart.) Kuntze by the alternate leaves, elliptic lamina with symmetrical base, absence of domatia, thyrsoid inflorescence, filaments connate at the base forming a staminal tube, asymmetrical capsule pubescent with velutinous trichomes, and one glabrous seed per valve, but differs by the pubescent stipules (vs. glabrous), leaves brown and papery when dry (vs. leaves pale green with a dark brown margin and coriaceous), cymules with 7 to 10 (15) flowers (vs. 3 to 4 [7]), and style sigmoid at the base (vs. style straight).

Description.

Trees or treelets 6–16 (20) m tall, terminal branchlets pubescent with appressed golden trichomes 0.1–0.3 mm long, glabrescent, with callose lenticels 0.3–0.5 mm long. Leaves alternate, petiolate; petiole 3–6 mm, pubescent with appressed golden trichomes 0.1–0.3 mm long; stipules deciduous, free, lanceolate, 2.5–6 × 1–1.5 mm, costa pubescent with appressed golden trichomes, 0.3–0.5 mm long, margin ciliolate, apex apiculate with mucron; lamina elliptic, 8–20 × 3–8 cm, foliaceous, adaxially glabrous, abaxially pubescent with appressed golden trichomes 0.1–0.3 mm long, glabrescent, semicraspedodromous, with 8 to 11 pairs of major secondary vein, secondary veins with equal spacing between them, base symmetrical, cuneate, margin subcrenate, apex acuminate, acumen 0.5–1.5 cm, mucronulate, leaf domatia absent. Inflorescence terminal, thyrsoid, solitary or often accompanied by one distinctly smaller lateral inflorescence, 5–15 × 3–5 cm, central axis brown, pubescent with appressed golden trichomes 0.1–0.3 mm long, cymules with 7 to 10 (15) flowers; common peduncle 3–8 mm; pedicels 1–2 mm long, articulated near the base, pubescent with appressed golden trichomes 0.1–0.2 mm long; bracts persistent, triangular, 1–1.3 × 1–1.3 mm, with prominent costa, costa pubescent with appressed golden trichomes 0.1–0.3 mm long, margin ciliolate, apex apiculate, mucronulate; bracteoles persistent, triangular, 1 × 1 mm, costate, costa pubescent with appressed golden trichomes 0.1–0.3 mm long, margin ciliolate. Flowers subzygomorphic, 2.5–3 × 2.5–3 mm; sepals triangular, 1.4–1.6 × 1.3–1.5 mm, without veins or costa, pubescent with appressed golden trichomes 0.1–0.2 mm long, margin ciliolate, apex apiculate; petals white, elliptic, 1.8–2.3 × 1.3–1.5 mm, costa pubescent with golden appressed trichomes 0.1–0.3 mm long, margin ciliolate, apex acute; stamens 1.6–1.8 × 0.9–1.2 mm, filament connate at the base forming a glabrous staminal tube with glands covering the filament, filaments 0.2–0.3 mm, anthers ovoid, 0.5–0.7 × 0.4–0.6 mm, glabrous, apex rounded, connective 0.5–0.7 mm, dorsal anther connective scale lanceolate, 1.3–1.5 × 0.8–1 mm, cream, margin entire, apex acuminate; ovary globose, 0.7–0.9 × 0.7–0.9 mm, pubescent with appressed golden trichomes 0.2–0.4 mm long; style filiform, curved at the base, 1–1.2 mm long, glabrous, stigma acute. Fruit an asymmetrical subligneous capsule dehiscent along three sutures, ellipsoid, 1–1.3 × 0.8–1 cm, apex acuminate, densely tomentose with golden trichomes 0.1–0.2 mm long. Seeds one per valve, ovoid, 4.5–5.5 mm diam., glabrous, shiny brown when dry (Fig. 3 ).

Distribution and habitat.

Rinorea idarragae occurs in Costa Rica and Panama in the Punta Arenas-Chiriquí and Guatuso-Talamanca biogeographical provinces (sensu Morrone 2014), respectively (Fig. 4 ). The species occurs in primary tropical wet forests, often on ridges, at elevations of 50– 300 m.

Etymology.

Rinorea idarragae is named in honor of Alvaro Idárraga Piedrahíta, director of the JAUM herbarium of the Botanical Garden Joaquin Antonio Uribe in Medellín. Idárraga has made many contributions to the floristic knowledge of Antioquia Department in Colombia and the taxonomy of the Araliaceae .

Phenology.

The species flowers and fruits throughout the year.

Conservation status.

Rinorea idarragae is known from 27 collections representing 21 occurrences. It has a geographic range in the form of an estimated EOO of 15,728 km 2 and an AOO of 64 km 2. While the species is well conserved in protected areas of the Osa Peninsula, Costa Rica, it is subject to mining and deforestation for timber extraction, agriculture, and grazing across the rest of its range in Panama. With regard to the most serious plausible threat of mining, the 21 occurrences represent 15 locations, and we project that ongoing mining and deforestation will lead to continuing decline in the area, extent and / or quality of habitat of the species. Nevertheless, the species does not meet the criteria for threatened status and is therefore preliminarily assessed as “ Near Threatened ” ( NT) in accordance with the IUCN Red List Categories and Criteria ( IUCN 2024).

Notes.

Rinorea idarragae can be differentiated from R. zygomorpha H. E. Ballard & Wahlert by its 3 to 5 × branched inflorescence (vs. 2 to 3 × branched), cymules bearing 7 to 11 flowers (vs. 3–5), smaller sepals 1.4–1.6 × 1.3–1.5 mm and sepals lacking veins or costa (vs. larger sepals 1.9–2 × 1–1.5 mm and sepals 3 - to 5 - veined), smaller elliptic petals 1.8–2.3 × 1.3–1.5 mm (vs. larger broadly oblong petals 3.2–3.8 × 1.2–1.3 mm), smaller stamens 1.6–1.8 × 0.9–1.2 mm (vs. 3–3.5 mm), and smaller dorsal anther connective scale 1.3–1.5 × 0.8–1 mm with margin praemorse (vs. 2.7–3.2 × 0.9–1.1 mm with margin entire).

Additional specimens examined.

Costa Rica. Prov. Puntarenas: • Reserva Forestal Golfo Dulce Camino saliendo de Rancho Quemado a Quebrada Baneguas , 08°40'48"N, 83°31'12"W, 100–200 m, 31 Aug 1991 (fl), R. A. Aguilar Fernández 291 ( CR, MO) ; • Mpio. Golfito, Estación Los Patos, Sendero Sirena , 08°33'36"N, 83°30'36"W, 200 m, 2 Jun 1994 (fr), R. A. Aguilar Fernández 3319 ( CR, MO) ; • Osa, fila llegando a Rancho Quemado , 08°42'36"N, 83°33'36"W, 200 m, 1 Nov 1994 (fr), R. A. Aguilar Fernández 3646 ( CR, MO) ; • Reserve Forestal Golfo Dulce, Península de Osa, fila Casa Loma, Cerro Chocuaco , 08°41'39"N, 83°29'38"W, 200–300 m, 14 Apr 1998 (fr), R. A. Aguilar Fernández 5405 ( CR, MO) ; • Canton Osa, Distrito Sierpe, Reserva Forestal Golfo Dulce, Rancho Quemado, camino a Chiqueron en la parte mas alta de la fila al sur de Rancho Quemado , 630 m, 11 Nov 2001 (fl), R. A. Aguilar Fernández 6709 ( NY) ; • Distrito Sierpe, Reserva Forestal Golfo Dulce, Rincón, Banegas camino a Rancho Quemado en la primer cuesta , 192 m, 23 Jul 2009 (fl), R. A. Aguilar Fernández 12214 ( NY) ; • fila before Rancho Quemado, near Rincon, Osa Peninsula , 08°42'N, 83°33'W, 300 m, 11 Jan 1993 (fr), A. H. Gentry et al. 78660 ( CR, MO) ; • Rancho Quemado, Fila División, entre Banegas y Rancho Quemado , 08°40'48"N, 83°32'24"W, 300 m, 16 Jul 1991 (fl, fr), J. Marín 12 ( CR, MO) ; • Reserva Forestal Golfo Dulce Osa Península, Rancho Quemado; in forest on trail to Drake on ridge at N end of valley, on slope leading down to Guerra , 08°43'48"N, 83°36'00"W, 200 m, 2 May 1988 (fl, fr), B. E. Hammel et al. 16785 ( CM, CR, MO, NY) ; • Reserva Forestal Golfo Dulce Osa Península, Rancho Quemado, ca. 15 km W of Rincón ; • at bottom of valley along Río Riyito near bridge and in forest along road on ridge above valley, 08°42'00"N, 83°33'00"W, 250–350 m, 31 May 1988 (fr), B. H. Hammel et al. 16904 ( MO) ; • along road between Rincón de Osa and Rancho Quemado, ca. 10 km W of main Rincón-Pto. Jimenez Road , 08°41'00"N, 83°32'30"W, 150–260 m, 3 Mar 1985 (fl), T. B. Croat 59768 ( CR, MO) ; • Rancho Quemado, finca de Jorge Cascante , 08°42'N, 83°34'W, 200 m, 5 Jul 1991 (fr), F. J. Quesada 524 ( MO) . Panama. Prov. Colón: • Teck Cominco Petaquilla mining concession, collected near plot C 003 , 08°50'22"N, 80°38'51"W, 184 m, 18 Sep 2007 (fr), G. D. McPherson 19677 ( MO, US, NY) ; • Teck Cominco Mining Concession, Camp Colina , along road, 08°49'24"N, 80°39'45"W, 274 m, 27 Feb 2008 (fr), M. C. Merello 3075 ( MO) ; • Teck Cominco Petaquilla mining concession, along road , 08°49'18"N, 80°39'35"W – 8°49'24"N, 80°39'48"W, 255–292 m, 28 Nov 2007 (fl), H. van der Werff 22177 ( MO, US) ; • San Juan del General, Conseción del Proyecto Mina de Cobre Panamá, Valle Grande , 08°49'18"N, 80°40'58"W, 280 m, 25 Jul 2014 (fl), J. de García et al. 796 ( MO, PMA) ; • Coclé del Norte , 09°04'30"N, 80°33'45"W, 100 m, 23 Aug 1978 (fl), B. E. Hammel 4460 ( MO) ; • Santa Rita Ridge, logging area 19 km from Transisthmian highway , 09°23'45"N, 79°39'15"W, 28 Jan 1968 (fr), J. W. Dwyer 8556 ( MO) ; • Santa Rita Ridge road, 4 mi from Transisthmian Highway to Agua Clara weather station , 09°21'N, 79°42'W, 500 m, 11 Dec 1973 (fl, fr), A. H. Gentry 8830 ( MBM, MO) . Prov. San Blás: • Río Cagandí, hills W of river S of confluence with Río Titamibe , 09°24'00"N, 79°06'00"W – 9°27'30"N, 79°07'00"W, 50–150 m, 27 Jan 1985 (fl), G. C. de Nevers et al. 4666 ( MO) ; • El Llano-Cartí road, north of Nusagandi, 2–6 miles , 09°15'N, 79°00'W, 250–300 m, 31 Mar 1988 (fl), G. D. McPherson 12392 ( MO, USCG) ; • Teck Cominco Petaquilla mining concession , 08°50'22"N, 80°38'51"W, 205 m, 18 Sep 2007 (fl), G. D. McPherson 19683 ( MO) ; • Teck Cominco Petaquilla mining concession , 08°49'28"N, 80°39'29"W, 190 m, 21 Sep 2007 (fl, fr), G. D. McPherson 19772 ( MO) ; • ibid., 08°49'18"N, 80°39'35"W, 255 m, 28 Nov 2007 (fl, fr), G. D. McPherson 19850 ( MO, US) ; • ibid., (fr), G. D. McPherson 19856 ( MO) ; • Teck Cominco Mining Concession, Colina Camp, along road , 08°49'23"N, 80°39'32"W, 101 m, 26 Feb 2008 (fl), M. C. Merello et al. 3058 ( MO) .

Figures

Figure 3. Rinorea idarragae Hoyos-Gómez A habit B detail of pubescence on young twig C detail of lenticels on young twig D detail of cymule E detail of flower with fused filaments F flower in bud G sepals, abaxial and adaxial surfaces H petals, detail of abaxial and adaxial surface I stamens, detail of abaxial and adaxial surfaces J gynoecium K fruit L detail of fruit M seed. (A – J: S. E. Hoyos-Gómez 1110 [HUA]; K – M: J. Marín 12 [CR]).

Figure 4. Distribution of Rinorea idarragae (stars) and R. paniculata (triangles).