Barbacenia glaucescens Ferreira-Junior & Andr.Cabral, 2023

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, Phytotaxa 616 (3), pp. 279-287 : 280-284

Barbacenia glaucescens Ferreira-Junior & Andr.Cabral sp. nov., ( Figs. 1A–G ; 2A–C ; 3C–D, I–J and N ; 4 ; table 1)

Type:— BRAZIL. Minas Gerais: Santana do Riacho, Serra do Cipó. Estrada Santana do Riacho—Lapinha ; 28 Jan. 1999; fl. & fr.; N.L. Menezes 1395 (holotype: SPF!; isotypes: BHZB!, RB!) .

Diagnosis: — Barbacenia glaucescens resembles B. gentianoides by the presence of spirotristichous leaves with overlapping length (5.4–13 cm and 3–8 cm, respectively), pedicel hidden by the leaves, tube of the hypanthium longer than the ovary and perianth red/orange (althougth it can vary between red, orange and yellow in B. gentianoides ). Moreover, B. glaucescens has glaucous and smooth leaves, the old ones twisted, and hypanthium covered with white trichomes (vs. bright green leaves with emergences on the midrib and margin, the old ones straight, and hypanthium covered with capitate-subulate emergences in B. gentianoides ).

Plant caespitose. Leaves spirotristichous, erect and becoming spirally twisted or rolled with age; adult blades 5.4–13 × 0.52–1.4 cm, linear-triangular to elliptical-triangular, glaucous, involute at the base and flat towards the apex, abscission line absent, apex long attenuate, margin with white-trichomes (sometimes only in the basal region), the old blades marcescent, reflexed and twisted. Flowers 1(-2); pedicel 5.5–6 mm long in the flowering, hidden by the leaves, cylindric, sparsely covered with white trichomes; hypanthium sparsely white-tomentose; section fused to ovary 13–16 × 3–4 mm, obovoid, light green to green; hypanthial tube 50–60 mm long, 7–10 mm wide at apex, lightred. Perianth predominantly red or red-orange, 23–41 × 3–5 mm, linear-lanceolate; sepals sparsely white-tomentose abaxially, adaxially smooth; petals smooth in both surfaces; corona lobes 14–18 × 2–3 mm, linear-lanceolate, red or red-orange, fused to the basal half, lobules 0.3–0.5 mm, asymmetric.Anthers 6–15 mm long, dorsifixed, attached to the corona apex, connective purple. Style 65–70 mm long, red, stigmatic regions 3, 1.6–1.8 mm long, confluent at apex. Capsule ca. 11 × 8 mm, widely ellipsoid. Seeds 0.7–1.3 mm long, rounded to slightly angulate, reddish brown.

Leaf and pedicel anatomy. Blade inconspicuously dorsiventral ( Fig. 3C–D ). Shallow furrows between the fibro-vascular bundles, more evident on the abaxial surface ( Fig. 3C–D ). Cuticle slightly thickened on both surfaces ( Fig. 3C–D ). Stomata present on both surfaces, mostly on abaxial one, in the region between fibro-vascular bundles ( Fig. 3C– D; I–J ). Epidermis uniseriate ( Fig. 3C–D ). Palisade mesophyll 2–3 cell-layer thick, grading into spongy parenchyma near fibro-vascular bundles and into aquiferous parenchyma in region between bundles ( Fig. 3C–D ). Fibro-vascular bundles surrounded by a distinct bundle sheath, 1–3 large vessels present in each fibro-vascular bundle ( Fig. 3C–D ). Phloem strands 2, separated by parenchymatous or sclerified cells ( Fig. 3C–D ). Fibers extending as girders next to epidermis on both sides, widely obtrapeziform in outline ( Fig. 3C ). Pedicel apparently circular in transverse section; fibro-vascular bundles 12; belt of sclerified cells not clearly seen ( Fig. 3N ). Leaf: Menezes 1395 and 1404, Arndt & Aristóbolo s.n SPF83677; pedicel: Menezes 1395.

Additional specimens examined (paratypes): — BRAZIL. Minas Gerais: Santana do Riacho; Vale à esquerda da estrada em direç„o a Lapinha; 1000 m; 08 Sept. 1990; fl.; Arndt & Aristóbolo s.n. SPF 83677 ( SPF!, BHCB). Ibid.: Lapinha da Serra, próximo ao trevo de retorno para Lapinha da Serra; 19º06’09.11”S, 43º41’56.17”W; 1127 m; 16 Abr. 2013; fl.; C. A. Ferreira-Junior 1235 ( BHZB!). Ibid.: RPPN Brumas do Espinhaço e Ermo das Gerais; 19 Abr. 2012; fl.; C. A. Ferreira-Junior 413 ( BHZB!). Ibid.: Serra do Cipó, a 7 km da bifurcaç„o para a Lapinha; 13 Oct. 1999; fl.; N.L. Menezes 1404 ( SPF!).

Distribution and habitat:— Barbacenia glaucescens is restricted to the municipality of Santana do Riacho, southern Espinhaço Range, Minas Gerais state, Brazil ( Fig. 4 ). This species occurs on rock outcrops of Serra do Cipó at elevations between 1000 and 1127 m. a.s.l.

Phenology: —Collected with flowers in January, April and between September and October and fruiting in January.

Preliminary conservation status:— There is not enough Barbacenia glaucescens information regarding spatial distribution to estimate its conservation status, therefore it is classified as Data Deficient (DD) according to IUCN (2012) criteria.

Etymology:— The epithet refers to the glaucous leaves, a character that differentiates the new species from the the bright green leaves of Barbacenia gentianoides .

Discussion:— Barbacenia glaucescens is similar to B. gentianoides ( Fig. 3A–B; G–H; M ) by its phyllotaxys, leaf length, pedicel exposure, hypanthium vs. ovary relative length, and perianth colour. However, these species can be promptly distinguished by their leaf colour (glaucous in B. glaucescens vs. bright green in B. gentianoides ), presence/absence of emergences on leaf-blade (absent in B. glaucescens vs. present in B. gentianoides ), and posture of the marcescent leaves (twisted in B. glaucescens vs. straight in B. gentianoides ), and type of surface covering on hypanthium (tector trichomes in B. glaucescens vs. capitate-subulate emergences in B. gentianoides ) (see also Table 1 ). These species also have different stomata distribution on the leaves (amphistomatic in B. glaucescens vs. hypohistomatic in B. gentianoides ) and vary in the presence or absence of furrows (present in B. glaucescens vs. absent in B. gentianoides ) ( Fig. 3 , Table 1 ). Although B. glaucescens has been described as having glabrous leaves, an envelope was found attached to the sample Menezes 1404 containing pieces of leaves with a pubescent indument, which does not match the exsiccate itself.

Figures

FIGURE 1. A–G. Barbacenia glaucescens (Menezes 1395). A. Habit. B. Leaf apex. C. Detail of leaf margin. D. Detail of the flower. E. Sepal apex. F. Petal apex. G. Corona lobes and stamens.H–R. Barbacenia mellosilvae (Pirani 5593). H. Habit.I. Leaf apex. J. Detail of the flower. K. Detail of the hypanthium, transition between the section fused to ovary and tube. L. Frontal view of the corona lobe and stamen. M. Detail of the corona lobules. N. Lateral view of the corona lobe and stamen. O. Apical portion of the style and confluent stigmatic regions. P. Sepal abaxial side. Q. Petal abaxial side. R. Immature capsule. Bar scale = 0.5 cm.

FIGURE 2.A–C. Barbacenia glaucescens. A. Population in its natural habitat. B. Habit. C. Flower in longitudinal view. D–F. Barbacenia mellosilvae. D. Population in its natural habitat. E. Flower in longitudinal view. F. Flower in top view.All photos by C.A. Ferreira-Júnior, except D by D. Zappi.

FIGURE 3. A, C and E. Cross section of median region of leaf. B, D and F. Cross section of the leaf midrib. G, I and K. Leaf abaxial epidermis. H, J and L. Leaf adaxial epidermis. M–O. Pedicel cross-section. A–B, G–H and M. Barbacenia gentianoides (Menezes 229, except for M, for which Menezes 419 was used). C–D, I–J and N. Barbacenia glaucescens (Menezes 1395). E–F, K–L and O. Barbacenia mellosilvae (Pirani 5593). Black bar scale = 200 μm; grey bar scale = 100 μm.

FIGURE 4. Distribution of Barbacenia glaucescens (black circle) and B. mellosilvae (white circle) in the Espinhaço Range, Minas Gerais state, Brazil.