Barbacenia mellosilvae Andr. Cabral & Ferreira-Junior. We 2023, sp. nov.
Creators: name: Cabral, Andressa
name: Ferreira-Júnior, Carlos Alberto
name: Menezes, Nanuza Luiza De
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Pandanales
Velloziaceae
Barbacenia
Barbacenia mellosilvae

description: Barbacenia mellosilvae Andr.Cabral & Ferreira-Junior sp. nov., (Figs. 1H–R; 2D–F; 3E–F, K–L and O; 4; table 1)
Type:— BRAZIL. Minas Gerais: Congonhas do Norte, Serra Talhada (setor nordeste da Serra do Cipó), 9 km S de Congonhas do Norte na estrada para Conceiç„o do Mato Dentro, entrada para Extrema seguindo 11 km – Fazenda Imbaúbas (propriedade do Sr. Helvécio Lacerda de Queiroz); 18°55’48”S, 43°40’17”W; 1130 m; 20 Jan. 2007; fl. & fr.; J.R.Pirani 5593, M.F.A. Calió, B.P.F. Loeuille & E.G. Martins (holotype: SPF!; isotypes: BHZB!, RB!, SP!).
Diagnosis: — Barbacenia mellosilvae resembles B. gentianoides by its spirotristichous leaves with overlapping length (2.6–12.2 cm and 3–8 cm, respectively), flowers with yellow perianth (this can vary from red, orange to yellow in B. gentianoides) and tube of the hypanthium longer than the ovary. However, this species can be distinguished by its flowers with free corona lobes (vs. predominantly fused by more than the basal half in B. gentianoides), yellow anthers (vs. purple to dark-purple), and pedicel evident (vs. hidden by the leaves).
Plant caespitose. Leaves spirotristichous, arcuate; adult blades 2.6–12.2 × 0.45–1 cm, linear-triangular to elliptical-triangular, lustrous, middle region flat, involute at the base and sightly involute towards the apex, abscission line absent, apex acute, sparsely covered with inconspicuous capitate-emergences on both surfaces, the old blades marcescent, reflexed but not twisted. Flowers 1–3; pedicel 10–45 mm long in the flowering, exposed, cylindric, sparsely covered with capitate-emergences; hypanthium sparsely covered with capitate-emergences; section fused to ovary 7–16 × 2–5 mm, ellipsoid, green; hypanthial tube 19–31 mm long, 3–6 mm wide at apex, yellow-greenish. Perianth yellow, 13–20 × 2–4 mm, elliptic-lanceolate; sepals abaxially sparsely covered with capitate-emergences, adaxially smooth; petals sparsely covered with capitate-emergences on the base and basal half of the midrib on abaxial surface, adaxial smooth; corona lobes 6–9 × 1.4–2.5 mm, linear-lanceolate, yellow, free, lobules 1.5–2.1 mm long, rounded-triangular at apex. Anthers 5.5–8 mm long, dorsifixed, attached to the corona apex, connective yellow. Style 29–51 mm long, yellow, stigmatic regions 3, 0.8–1.2 mm long, confluent at apex. Capsule 11–15 × 7–8 mm, globose-ellipsoid. Seeds 0.5–0.8 mm long, rounded to slightly angulate, reddish brown.
Leaf and pedicel anatomy: — Blade inconspicuously dorsiventral (Fig. 3E–F). Furrows absent (Fig. 3E–F). Cuticle slightly thickened on both surfaces (Fig. 3E–F). Stomata present on both surfaces, in the region between fibro-vascular bundles (Fig. 3E–F; K–L). Epidermis uniseriate, with capitate-emergences on both sides (Fig. 3E–F; K–L). Palisade mesophyll 2–4 cell-layer thick, grading irregularly into spongy parenchyma and aquiferous parenchyma (Fig. 3E–F). Fibro-vascular bundles surrounded by a distinct bundle sheath, 1–3(–4) large vessels present in each fibro-vascular bundle (Fig. 3E–F). Phloem strands 2, separated by parenchymatous cells (Fig. 3E–F). Fibers extending as girders next to epidermis on both sides, shorter in the abaxial side, narrowly obtrapeziform in outline in the adaxial side (Fig. 3E–F). Pedicel circular in transverse section; fibro-vascular bundles 16; belt of sclerified cells present (Fig. 3O). Leaf: Mello-Silva 3397, Pirani 5593, Zappi 2744; pedicel: Mello-Silva 3397, Pirani 5593.
Additional specimens examined (paratypes): — BRAZIL. Minas Gerais: Santana de Pirapama, Serra do Cipó, Capela de S„o José, Subida de Senhorinha; 18°56’54”S, 43°45’22”W; 1354 m; 6 Mar. 2010; fl.; D. Zappi 2744 (SPF!) • ibid., Inhame, Serra do Cipó, Trilha da Senhorinha; 18°56’13.7”S, 43°45’14.9”W; 1311 m; 21 Mar. 2011; fl. & fr; R. Mello-Silva 3397 (SPF!).
Distribution and habitat: — Barbacenia mellosilvae can be found in the campo rupestre of the nortwestern part of the Serra do Cipó, in the municipalities of Congonhas do Norte and Santana de Pirapama, southern Espinhaço Range (Fig. 4). This species occurs as large populations on rock outcrops, sometimes on riparian rocks (Pirani 5593), and on white gravelly soil, at elevations from 1130 to 1354 m. a.s.l.
Phenology: —Collected with flowers and fruits in January and March.
Preliminary conservation status: — Barbacenia mellosivae is only known by two populations in the Serra do Cipó region, although none of them fall within the limits of the nearby protected areas (i.e., Serra do Cipó State Park and Serra do Intendente State Park). In addition to not being legally protected, its suitable habitat is likely to be under continuing decline of area and quality due to tourism, mining and livestock ranging, and invasion of exotic species (Ribeiro et al. 2005, Ribeiro & Freitas 2010, Gualtieri-Pinto et al. 2008). Therefore, considering its Area of Occupancy (12 km 2) and Extent of Occurrence (5,35 km 2) under the IUCN (2012) criteria, B. mellosilvae can be classified as Critically Endangered, CR B1ab(iii)+2ab(iii).
Etymology:— The epithet is a homage to Renato Mello-Silva (in memoriam), a renowned Brazilian botanist who dedicated almost four decades of his research to the study of the biodiversity of Brazilian mountains and Systematics of Velloziaceae and Annonaceae.
Discussion:— Barbacenia mellosilvae resembles B. gentianoides by its phyllotaxys, leaf length, hypanthium vs. ovary relative length, and sometimes by its perianth colour (yellow perianth, but that can also be orange or orangereddish in B. gentionoides). Barbacenia mellosilvae, however, can be easily distinguished by its flowers with free corona lobes (vs. fused by more than the basal half in B. gentianoides), yellow anthers (vs. purple to dark-purple), and pedicel evident (vs. hidden by the leaves), table 1. The species can also be identified by anatomical characters (Fig. 3; Table 1), such as amphistomatic leaves (vs. hypostomatic in B. gentianoides) and pedicel with 16 vascular bundles (vs. 12 vascular bundles). The combination of spirotristichous leaves, emergences on leaves and flowers, yellow perianth and evident pedicel can also be found in B. longiflora. These species can be distinguished by the distribution of emergences on leaves (laminae sparsely covered with emergences in both surfaces in B. mellosilvae vs. emergences only on the midrib and margin in B. longiflora), emergences density in pedicel and hypanthium (sparse in B. mellosilvae vs. dense in B. longiflora), pedicel maximum length (4.5 cm long in B. mellosilvae vs. 9 cm in B. longiflora) and hypanthial tube maximum length (3.1 cm long in B. mellosilvae vs. 4.53 cm in B. longiflora). Besides that, unlike B. mellosilvae, B. longiflora can display a range of perianth colours varying from red and orange to yellow.
description: Published as part of Cabral, Andressa, Ferreira-Júnior, Carlos Alberto & Menezes, Nanuza Luiza De, 2023, Two new remarkable species of Barbacenia (Velloziaceae) from the Brazilian Espinhaço Range in honor of Renato Mello-Silva, pp. 279-287 in Phytotaxa 616 (3) on pages 284-286, DOI: 10.11646/phytotaxa.616.3.7, http://zenodo.org/record/10085083