Randia sulbahiana R. Borges, J. G. Jardim & R. M. Salas, nom. nov.
Creators: name: Borges, Rodrigo Lopes
name: Roque, Nádia
name: Jardim, Jomar Gomes
name: Salas, Roberto Manuel
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Gentianales
Rubiaceae
Randia
Randia sulbahiana

description: Randia sulbahiana R.Borges, J.G.Jardim & R.M.Salas, nom. nov.
Sphinctanthus insignis Steyerm., Brittonia 33: 400. 1981. (Figures 3 and 4)
Type:— BRAZIL. Bahia: Guaratinga, plantação de cacau, 8 October 1966, R.P. Belém & R.S. Pinheiro 2738 (holotype: VEN 134002 [digital image!]; isotypes: IAN 120642!, NY 17098!, RB 135392!, RB 140584!, UB 159679 [digital image!]).
Description:— Shrubs or treelets, 3–8 m tall; branches erect, occasionally scandent, striate, bark peeling on the older portions, thorny, frequently bearing up to two thorns on branches, occasionally without thorns, covered by stipules on the distal portion; thorns 3–6 mm long, smooth, brown to reddish, glabrous. Stipules deciduous, persistent on brachyblasts, triangular to ovate, 4–8 mm long, striate, margin entire, glabrous, leaving marks on the brachyblasts after falling. Leaves decussate, petiolate; petiole 0.6–1.5 cm long, canaliculate, strigillose to puberulous; leaf blade 9–17 × 3–7 cm, elliptic to lanceolate, apex acuminate, base attenuate, membranous, glabrescent, pubescent over the veins, discolor, becoming blackish when dry, ferruginous over the main and secondary veins, 7–12 secondary veins on each side; leaf domatia absent. Male inflorescences with flowers organized in sessile fascicles, up to three flowers; flowers releasing a strong scent, pedicellate, pedicel 1.0– 1.2 cm long, puberulent to glabrescent, releasing a strong scent; hypanthium obconic, glabrescent; calyx 5-lobed, lobes narrowly triangular, 7–10 × 1 mm, green, becoming blackish when dry, glabrescent; corolla infundibuliform 4–6 cm long, tube greenish, expanding at mouth region, 2.3– 2.6 cm long, glabrescent; corolla lobes elliptic, 2.2–3.1 × 0.6–0.8 cm, apex acute, white, yellowish on the mouth when receptive, glabrescent externally, tomentose internally; stamens 5, sub-included; style larger than the corolla tube, style two-lobed, non-functional, ovary rudimentary. Female inflorescence not observed. Fruit globose, with persistent calyx, 2.3–3.9 × 2.4–2.9 cm, yellow in maturity, passing to black when dried, glabrous. Seeds lenticular, flattened, pilled, surrounded by a fleshy mesocarp which turns black when dried, smooth, brown, glabrous.
Distribution and Ecology:— Randia sulbahiana occurs in south of Bahia, in the Atlantic rainforest, generally in montane forests above 500 m elevation (Figure 2).
Phenology:— The male individuals of this species are found with flowers between October and November, developing fruits from March to June. Specimens with female flowers have not been collected, a pattern we associate to the ephemerous nature of pistillate flowers in Randia, being observed among many species in this genus (Gustafsson 2000).
Etymology:— The epithet sulbahiana refers to the occurrence of this species in the Atlantic rainforest, in southern Bahia, Brazil. This area harbors high levels of endemic and threatened species, being considered one of the main centers of endemism in the Atlantic Forest (Thomas et al. 1998).
Preliminary Conservation Status:— R. sulbahiana is considered Endangered (EN), considering the criteria of Area of Occurrence (AOO), and Extent of Occurrence (EOO) (AOO 40.000 Km² and EOO 3,022.109 Km²). Collections of this species are registered in 22 localities, 20 of them occur in Conservations Units (Serra do Teimoso private reserve, Serra Bonita private reserve, Serra das Lontras National Park, and Una National Park), thus new studies with Rubiaceae in the Atlantic Forest are necessary to reveal the distribution of R. sulbahiana. This species occurs only in preserved remnants, threatened by rapid deforestation due to logging and agricultural activities. Based on the distribution inferred in this study, in addition to the environmental pressures identified in the area of occurrence, this species would be classified as EN: B1a,b(iii).
Nomenclatural status:— Sphinctanthus is recognized for bearing bisexual flowers, corolla normally yellow to orange, constricted below the mouth, and a ring of trichomes near the base (Salas et al. 2022). Sphinctanthus insignis was characterized by Steyermark (1981) for having the interior of the corolla densely pubescent, mainly on the upper portion, a feature not observed in this genus. We observe thorns and unisexual flowers on the holotype, with male flowers organized in fascicles, features which are enough to place this taxon in Randia. Considering all morphological characters detailed above, and the fact the name Randia insignis Valeton (1907: 63) is already used (ICN; Art. 6.11; Turland et al. 2018), we propose a new name to this species (Randia sulbahiana R.Borges, J.G.Jardim & R.M.Salas).
Comments:— Randia sulbahiana is comparable with R. adolphoduckei R.M. Salas (2022: 150) and Randia armata, sharing similarity on the acute apex of floral buds and corolla lobes. It shares with R. adolphoduckei many similarities such as: the facultative presence of thorns; absence of leaf domatia; stipules early caducous, and linear or filiform calyx lobes, and differing because of the leaves puberulent abaxially, especially on veins, 7–12 secondary veins, turning blackish or dark green when dry (vs. leaves glabrous, 10–17 secondary veins, turning olive green when dry in R. adolphoduckei), male inflorescence 3-flowered, sessile, fasciculate (vs. inflorescences 4-flowered, pedunculate, cymose), and male flower with corolla 4–6 cm long. (vs. corolla 7–8.5 cm long.). From R. armata, it differs in having glabrous or glabrescent leaves (vs. adpressed-pubescent leaves, especially on veins in R. armata), male flower with linear calyx lobes, 7–10 mm long [vs. narrowly oblong, elliptic, or obovate, (5–) 10–25 mm long], and corolla glabrous externally (vs. corolla adpressed-pubescent outside).
Specimens examined:— BRAZIL. Bahia: Arataca, Serra do Peito-de-Moça. Estrada que liga Arataca à Una, ramal ca. 22,4 km de Arataca, com entrada no Assentamento Santo Antônio, RPPN “Caminho das Pedras”, 15°10’25’’S, 39°20’30’’W, 1000 m, 24 September 2006, A. M. Amorim et al. 6359 (CEPEC); ibid., 22 November 2007, F. M. Ferreira et al. 1412 (CEPEC); Serra das Lontras, ca. 7 km no ramal que liga o distrito de Itatinguí à Serra, ramal de acesso à Fazenda Véu de Noiva, de propriedade de José Marques, 15°10’25’’S, 39°20’30’’W, 1000 m, 21 January 2007, R. A. X. Borges et al. 609 (CEPEC, JPB); ibid., PARNA Serra das Lontras, 15°08’56’’S, 39°19’03’’W, 600–950 m, 16 February 2012, A. M. Amorim et al. 8113 (CEPEC); ibid., Serra das Lontras, Topo da montanha, 15°11’22’’S, 39°23’07’’W, 700–900 m, 6 February 2009, R. O. Perdiz et al. 310 (CEPEC, HUEFS); ibid., Serra Novo Javi, entrada 9,5 km N, mais 8,9km até a sede da RPPN, Trilha da Serra, acesso ca. 1,5km NE da sede, Topo da Serra, 15°10’42’’S, 39°20’09’’W, 759 m, 12 September 2009, L. Daneu et al. 112 (CEPEC); Rod. Arataca / Una, entrada 9,5km N, Fazenda Oreon 6 km da entrada, trilha margeando o rio, 8 November 2008, J. G. Jardim et al. 5438 (CEPEC); Barro Preto, Serra da Pedra Lascada, 13,7 Km de Barro Preto, na estrada que passa pela Fazenda São Miguel, em direção à serra, Meio da encosta, 14°46’13’’S, 39°12’10’’W, 600–900 m, 3 October 2006, M. M. M. Lopes et al. 1099 (CEPEC). Camacã, RPPN Serra Bonita, 9,7 km W de Camacã na estrada para Jacarecí, 6 km SW na estrada para a RPPN e torre da Embratel, 15°23’30’’S, 39°23’55’’W, 850 m, 5 June 2005, J. L. Paixão et al. 429 (CEPEC); 9,7 km W de Camacã na estrada para Jacarecí, daí 6 km SW na estrada para a RPPN e torre da Embratel, trilha nova que vai da base da torre ao alojamento, 15°23’30’’S, 39°23’55’’W, 835 m, 30 October 2005, A. M. Amorim et al. 5451 (CEPEC, HUEFS); ibid., 9 July 2005, A. M. Amorim et al. 5147 (CEPEC); ibid., 3 March 2006, A. M. Amorim et al. 5719 (CEPEC); ibid., trilha do Mirante, 6 June 2006, M. M. M. Lopes et al. 820 (CEPEC, HUEFS); ibid., 4 February 2005, M. Reginato et al. 222 (CEPEC, HUEFS). Itapebi, rod. Ventania-Itapebi, pasteria, November 1967, R. S. Pinheiro & T. S. Santos 382 (ALCB, CEPEC, HUEFS, IPA, MBM, US 2869004, US 2869017). Jussari, RPPN Serra do Teimoso, ca. 7,5 km de Jussari, na Rod. para Palmira, 15°9’37’’S, 39°32’10’’W, 2 November 2002, J. G. Jardim et al. 4042 (CEPEC, HUEFS); ibid., rod. Jussari / Palmira, entrada ca. 7 km da cidade, faz Teimoso, 15°9’37’’S, 39°32’10’’W, 24 February 2005, J. G. Jardim et al. 4498 (CEPEC); ibid., 10 December 2004, A. M. Amorim et al. 4469 (CEPEC); Santa Luzia / Una, entrada a 11,3 km a E da Sede do município “Serra da Onça”, 4,5 km da estrada, 510 m, 10 May 1998, A. M. Amorim et al. 2444 (CEPEC, NY). Una, Ribeiro das Palmeiras, Serra Javi, ramal com entrada no km 11 da rod. São Jose / Una, lado S a 9 km até cima da serra, 9 km por ar SSE São Jose, 15°09’S, 38°18’W, 600–700 m, 6 March 1986, T. S. Santos et al. 4159 (CEPEC, US); ibid., Serra Javi, 15°07.5’’ S, 38°19’W, 400–700 m, 28 March 1986, T. S. Santos et al. 4069 (CEPEC).
description: Published as part of Borges, Rodrigo Lopes, Roque, Nádia, Jardim, Jomar Gomes & Salas, Roberto Manuel, 2024, Novelties in Randia L. (Gardenieae, Rubiaceae) from Brazil, pp. 43-54 in Phytotaxa 645 (1) on pages 47-50, DOI: 10.11646/phytotaxa.645.1.4, http://zenodo.org/record/13214848