﻿Seven new species of Rinorea (Violaceae) from the Neotropics

﻿Abstract Over the course of revising the genus Rinorea (Violaceae) from Colombia, field observations and herbarium studies revealed seven new species. Several of the new species described here belong to species complexes that required examination of herbarium material from across the Neotropics. Each of the new species described here have oppositely arranged leaves and belong to Rinoreasect.Pubiflorae, a section restricted to the Neotropics. Two new species are segregated from the R.ovalifolia species complex: Rinoreachiribiquetensis from Chiribiquete National Park in the Colombian Amazon and Rinoreastevensii from the Orinoco River near the border of Colombia and Venezuela. Two new species are segregated from the Rinoreahirsuta species complex: Rinoreagaleanoae-bernalii and Rinoreacogolloi, both from the eastern slopes of the Andean Central Cordillera along the mid-Magdalena River Valley in Colombia. From the widely distributed R.pubiflora species complex, we segregated one new species, Rinoreacallejasii, from southeast Panama and the Chocó in Colombia. In addition to these five new taxa segregated from widely distributed species complexes, we discovered two previously unknown species with affinities to other Neotropical Rinorea. Rinoreaaymardii is described from the Alto Orinoco-Casiquiare Biosphere Reserve in Venezuela and most closely resembles R.melanodonta from Colombia. Rinoreabetancurii is segregated from R.macrocarpa and occurs in the Amazonian Regions of Colombia, Brazil, Peru and Venezuela. In this study, we provide descriptions, illustrations and distribution maps of the new species and make preliminary assessments of the risk of extinction using the IUCN Red List Categories and Criteria. We also furnish an identification key to the species of Rinoreasect.Pubiflorae in Colombia.


Introduction
The genus Rinorea Aubl.has a pantropical distribution and is the second largest genus in the Violaceae after Viola (Ballard et al. 2014).It is composed of 225-275 species of shrubs and trees with ca. 30 species in Asia, 115-155 species in Africa, 24 species in Madagascar and, in the Neotropics, where species of Rinorea typically occur in lowland rainforests, 47 species and two infraspecific taxa are currently recognised (Hekking 1988;Wahlert and Ballard 2009;Wahlert 2010; Marquete Ferreira da Silva and Medeiros 2012; Oliveira and de Queiroz PhytoKeys 242: 241-271 (2024), DOI: 10.3897/phytokeys.242.110474Saúl E. Hoyos-Gómez et al.: Seven new species of Neotropical Rinorea 2020).They are often locally common shrubs and treelets of the forest understorey and frequently co-occur with other species of Rinorea (ter Stegee 2013).
In his taxonomic treatment of Neotropical Rinorea, Hekking (1988) classified the species into one of two groups: Super Group I 'Apiculata' and Super Group II 'Rinorea.'The three species in Super Group I 'Apiculata' were segregated into the genus Bribria Wahlert & H.E. Ballard, based on morphological, anatomical and molecular phylogenetic evidence (Wahlert et al. 2017;Wahlert and Ballard 2012;van Velzen et al. 2015).Hekking divided Super Group II 'Rinorea' into three groups: Group IIa 'Rinorea,' Group IIb, 'Uxpanapana,' and Group IIc 'Pubiflora ' Hekking (1988).Wahlert et al. (2017) established these groups as taxa: Group IIa was recognised as Rinorea sect.Rinorea and includes all Neotropical Rinorea with alternately arranged leaves, Group IIb was segregated into the genus Ixchelia H.E. Ballard & Wahlert, with two species from Mexico and Mesoamerica and Group IIc was recognised as Rinorea sect.Pubiflorae Wahlert & H.E. Ballard and includes all Neotropical Rinorea with oppositely arranged leaves.The seven new species described in this study all belong to R. section Pubiflorae, which is endemic to the Neotropics.
The present study was undertaken as part of a revision of Rinorea for Colombia.However, because several taxa are allied to widely distributed complexes, we examined specimens from across the Neotropics, from Mexico to Brazil and the Caribbean.We employed many of the same traits used by Hekking (1988) to circumscribe taxa and we found that previously overlooked characters of lamina venation are also useful in delimiting some species of Rinorea.The venation characters used in this study include details of the patterning of primary and tertiary veins and the spacing and angle of attachment of the secondary veins to the mid-vein, amongst others.In addition to three species discovered since Hekking's (1988) monograph, the seven new species described here bring the total number of taxa in Rinorea sect.Pubiflorae to 44 (41 species and three infraspecific taxa).The 13 remaining Neotropical species, all with alternate leaves, belong to R. sect.Rinorea.

Materials and methods
Field collections were made in lowland tropical rainforests in Bolivia, Colombia, Costa Rica and Peru, from 0-500 m elevation.All available herbarium material was examined from BHO, COAH, COL, F, FAUC, GH, HUA, JAUM, MEDEL, MO, NY, TOLI, UBDC and US (herbarium acronyms according to Thiers (2023)).Several digitised herbarium collections and records from the Global Biodiversity Information Facility (GBIF) were consulted to locate duplicate specimens for the following Herbaria: AAH, CM, FMB, G, INPA, K, MA, MBM, MG, MICH, RB, P, U and VEN.All cited collections have been seen by the first author.Species descriptions are based primarily on field observations and herbarium specimens.When available, flowers from herbarium specimens were rehydrated before dissection and measurement.A digital caliper and dissecting stereoscope were used to measure indument, flowers, fruits and seeds.
Leaf laminae were cleared to study venation architecture.Leaves were placed in a glass container and submerged in 1-5% sodium hydroxide (NaOH).The NaOH solution was changed every 1-2 days during the clearing process, which took 8-10 days.Leaves were then washed in a 50% Clorox ® solution followed by a final wash in water to stop the bleaching process.Staining was made with safranin for 5-8 minutes and then the leaves were put through a dehydration series in 50%, 95% and 100% ethanol (Ellis et al. 2009).The cleared leaves were photographed with a digital camera using a scale bar.
Post-factum georeferences for specimens lacking coordinates were assigned using either Google Earth or Tropicos specimen records with the same collecting localities.Collections lacking unambiguous locality information were omitted from the conservation assessment calculations.The online GeoCat facility (Bachman et al. 2011) was used to calculate the Extent of Occurrence (EOO) and Area of Occupancy (AOO) of each species to preliminarily estimate the risk of extinction using IUCN Red List Categories and Criteria (IUCN 2012); a 2 × 2 km cell was used for calculating AOO.
Phenology.The species flowers January through March; specimens in fruit were collected in March and May.
Conservation status.Rinorea callejasii has a geographic range in the form of an EOO of 40,729 km 2 and AOO of 52 km 2 .In Panama, it is represented by two locations within Chagres National Park and one location in Soberanía National Park.Outside of the protected areas, where the species exists at nine locations, it is threatened by the exploitation of natural resources, mineral extraction and energy development.In Colombia, it is represented by two locations, both outside protected areas.The species does not meet the criteria necessary to assign a threatened status.However, given ongoing habitat disturbance, it is likely that the species will qualify in the near future for a threatened status and, thus, it is preliminarily assessed with a status of "Near Threatened" (NT).
Notes.Rinorea pubiflora, as circumscribed by Hekking (1988), was morphologically variable across its large distribution in the Neotropics.He recognised a variety of R. pubiflora: var.grandifolia (Eichler) Hekking, which was further divided into two forms: f. grandifolia and f. andersonii (Sandwith ex Hekking) Hekking.Rinorea callejasii is a segregate of R. pubiflora var.pubiflora s.s.In attempting to explain the morphologically divergent specimens of var.pubiflora from Panama (e.g.G. C. de Nevers et al. 5075), Hekking (1988) invoked a scenario of hybridisation between R. squamata S.F.Blake and var.pubiflora.However, our analysis of morphological divergence and biogeographic distribution suggest that R. callejasii is a separately evolving lineage from the nominate species (sensu De Queiroz (2008)) and deserving of recognition as a new taxon at the rank of species.
Phenology.The species is only known from one flowering specimen collected in February.
Conservation status.Rinorea aymardii has a geographic range in the form of an EOO of 4 km 2 and AOO of 4 km 2 .It is currently known only from the type collection, which represents one location within the terra firma forests of the Alto Orinoco-Casiquiare Biosphere Reserve in Venezuela where it is threatened by illegal logging and mining.Based on its limited AOO, the single location and the projected continuing decline in the quality of habitat due to uncontrolled deforestation and resource extraction, the species might be preliminarily assigned to the "Critically Endangered."However, given the difficulty accessing this inadequately explored area, it is likely there are additional occurrences that would allow a more accurate assessment of the risk of extinction than is possible at this time.The species is therefore preliminarily assigned to the IUCN (2012) Category of "Data Deficient" [DD].
Phenology.The species is only known from one flowering specimen collected in December.
Conservation status.The region encompassing the vast and remote Chiribiquete National Park is relatively little explored as evidenced by the scarcity of collections in the Tropicos database (https://www.tropicos.org;accessed 25 February 2023), GBIF (https://www.gbif.org;accessed 25 February 2023) and other Colombian Herbaria (e.g.COAH, COL, HUA).There are insufficient data to assess the risk of extinction of Rinorea chiribiquetensis and, therefore, the species is preliminarily assigned to the IUCN (2012) category of "Data Deficient" [DD].

Vernacular names. Aruni yó (B. M. Boom et al. 6564).
Conservation status.Rinorea stevensii has a geographic range in the form of an EOO of 5,070 km 2 and AOO of 56 km 2 .It is represented by two locations within the El Tuparro National Park in Colombia and eight locations outside of protected areas in Venezuela where it is threatened by deforestation, illegal resource extraction and uncontrolled fires.Based on its limited AOO, the number of locations and the projected continuing decline in the quality of habitat, the species is preliminarily assigned to the "Vulnerable" category [VU B2ab(iii)].
Notes.Based on several morphological differences and an allopatric distribution, Rinorea stevensii is segregated from R. ovalifolia (as circumscribed by Hekking (1988)).Hekking noted the variable morphology of some specimens now representing R. stevensii, but he was unsure of their placement: "The leaves of Rinorea ovalifolia are variable in character, e.g. the underside of the leaves varies from densely hispidulous to glabrescent and domatia may be present or not".Hekking invoked introgressive hybridisation between R. ovalifolia and R. pubiflora var.pubiflora to explain the morphological variability, but we disagree with his opinion.We hypothesise that the distinctive morphological characteristics and the discrete biogeographic distribution suggest that R. stevensii is a separately evolving lineage (sensu De Queiroz (2007)) making it worthy of recognition at the rank of species.Key morphological differences amongst R. stevensii, R. ovalifolia and R. pubiflora var.pubiflora are presented in Table 1.
Phenology.The species flowers between August and December; fruiting specimens were collected in February and August through October.
Conservation status.Rinorea cogolloi has a geographic range in the form of an EOO of 1,641 km 2 and AOO of 32 km 2 .It is currently known from eight locations outside of protected areas.The region, underlain by karstic rocks, is heavily impacted by limestone extraction for concrete production and uncontrolled deforestation for grazing, agriculture and logging.Another location in north-eastern Antioquia Department is threatened with gold mining and deforestation.Given the high demand for cement products, the generally poor management of forest resources in the area and the number of locations, we project a continuing decline in the extent and quality of habitat for the species.Rinorea cogolloi is preliminarily assigned to the "Vulnerable" category [VU B1+B2ab(iii)] in accordance with the IUCN Red List Categories and Criteria (IUCN 2012).
Notes.Hekking (1988) noted the aberrant lamina pubescence of several specimens of Rinorea lindeniana (e.g. A. Cogollo 786, 1075Cogollo 786, , 1483)).Rinorea cogolloi and R. lindeniana share several characteristics, such as leaf venation architecture and asymmetrical lamina bases, but R. cogolloi is readily separated from R. lindeniana by the densely pubescent indument on the abaxial lamina surface (vs. the abaxial lamina surface pilose to glabrescent in R. lindeniana).Rinorea cogolloi occurs sympatrically with R. galeanoae-bernalii (see below), but R. cogolloi has densely pubescent indument on the abaxial lamina surface (vs.abaxial lamina surface glabrescent in R. galeanoae-bernalii), pubescent fruit with spreading, erect ferruginous trichomes 0.3-0.4mm long (vs.densely tomentose fruit) and the seeds pubescent with erect ferruginous trichomes 0.3 mm long (vs.seeds glabrous).Rinorea cogolloi and R. hirsuta have been confused by the similarity of the leaves and indumenta, but they can be differentiated by the asymmetrical lamina base, thyrsoid inflorescence, dorsal gland pubescent, pubescent seeds and capsule asymmetrical and pilose.In addition, Description.Rinorea galeanoae-bernalii is similar to R. hirsuta by the elliptic lamina with symmetrical base and lacking domatia, inflorescence racemose, capsule symmetrical and pubescent with velutinous trichomes and one glabrous seed per valve, but it differs by the abaxial surface of the lamina glabrescent (vs.abaxial surface of the lamina pubescent with ferruginous trichomes in R. hirsuta), filaments fused at the base forming a staminal tube (vs.filaments free not forming a staminal tube), anthers with pubescence between the thecae (vs.anthers glabrous between the thecae) and style proximally pubescent (vs.style proximally glabrous).
Phenology.The species flowers between July and October; fruiting specimens were collected in January, April, July and September through November.
Conservation status.Rinorea galeanoae-bernalii has a geographic range in the form of an EOO of 9,409 km 2 and AOO of 48 km 2 .It is known from 11 locations that are not included in any protected area.The locations in the middle Magdalena River Valley are heavily impacted by deforestation for grazing and agriculture, especially for cultivation of Elaeis guineensis (oil palm), while  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).
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

Figure 1 .
Figure 1.Rinorea callejasii Hoyos-Gómez A habit B detail of young twig with pubescence C detail leaf showing domatia, abaxial surface D leaf architecture E inflorescence F flower G sepals, abaxial surface H petals, abaxial surface I stamens, adaxial surface J gynoecium K infructescence L fruit, showing two seeds per valve M seed.(A-J: M. D. Correa 765 [MO]; K-M: G. D. McPherson 6851 [MO]).

Figure 5 .
Figure 5. Rinorea chiribiquetensis Hoyos-Gómez A habit B detail of young twig with pubescence C detail of young twig showing lenticels D detail of leaf showing pubescence, adaxial surface E detail of leaf showing domatia, abaxial surface F leaf architecture G infructescence H flower I sepals, abaxial surface J petals, abaxial surface K gynoecium L stamens, showing adaxial and abaxial surfaces, with a detail of the dorsal gland (left).(A-L: M. Velayos 6509 [MO)].

Figure 7 .
Figure 7. Rinorea stevensii Hoyos-Gómez A habit B detail of young twig showing lenticels and pubescence C detail of leaf showing domatia, abaxial surface D detail of leaf showing margin ciliate, adaxial surface E branchlet with inflorescences F leaf architecture G infructescence H flower I sepals, abaxial surface J petals, abaxial surface K stamens, showing adaxial and abaxial surfaces L gynoecium M fruit N detail of fruit showing two seeds per valve O seed.(A-D: B. M. Boom 6564 [MO]; E-O: J. L. Zarucchi 3577 [MO]).

Figure 8 . 6 .
Figure 8. Rinorea cogolloi Hoyos-Gómez A habit B detail of leaf pubescent, abaxial surface C leaf architecture D infructescence E cymule with flowers F sepals, abaxial surface G petals, abaxial surface H stamens, showing adaxial and abaxial surfaces I gynoecium J infructescence K detail of fruit showing one seed per valve L seed.(A-L: A. Cogollo 786 [MO]).

Figure 10 .
Figure 10.Rinorea galeano-bernalii Hoyos-Gómez A habit B detail of leaf, abaxial surface C leaf architecture D infructescence E flower F detail of filaments fused at the base forming a staminal tube G sepals, abaxial surface H petals, abaxial surface I stamens, adaxial and abaxial surfaces J detail of anthers showing pubescence between the thecae K gynoecium L fruit M detail of fruit showing one seed per valve N seed.(A-E, N: D. Sanin 7704 [HUA]; D. Sanin 7966 [HUA]).

Figure 11 .
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]).