Vochysia sobralii G.H.Shimizu & D.J.P.Gonç., 2022

Shimizu, Gustavo Hiroaki & Gonçalves, Deise Josely Pereira, 2022, Vochysia sobralii (Vochysiaceae), a new species from Serra do Cachimbo, Pará, Brazil, and updated keys for Vochysia sect. Pachyantha, Phytotaxa 542 (2), pp. 207-213 : 208-209

Vochysia sobralii G.H.Shimizu & D.J.P.Gonç. , spec. nov. ( Figures 1–3 )

Vochysia sobralii is characterized by presenting opposite leaves or in 3-merous whorls, petioles longer than 1 cm, leaf blades longer than 13 cm, elliptic, with cuspidate apex and cuneate base.

Type: — BRAZIL. Pará: Altamira, Serra do Cachimbo, December 2005, fl., M. Sobral & A. G. Oliveira 10876 (holotype HUEFS108806 ! [mounted on two sheets], isotype MBM barcode 312865!) .

Trees, 15–20 m tall. Branchlets quadrangular or subterete, ferrugineous tomentellous, cortex not exfoliating. Leaves opposite or in 3-merous whorls; stipules ca. 0.5 cm long, deltoid, tomentellous, caducous; petiole 1.1–1.7 cm long, pilose; leaf blade 13.5–19 × 4–6.2 cm, elliptic, chartaceous; adaxial surface glabrous, shiny, midrib impressed and secondary veins prominulous; abaxial surface tomentellous, midrib and secondary veins prominent, intersecondary veins less prominent, tertiary veins reticulate, also less prominent, marginal vein about 0.5–1 mm from the leaf margin, undulate; apex cuspidate, base cuneate, margin flat to subrevolute. Inflorescence a thyrse of cincinni, terminal, 19–25 cm long, tomentellous; cincinni 1-florous, peduncle ca. 0.3 cm long and pedicel ca. 1 cm long; bracts caducous. Flower bud ca. 2 × 0.2 cm, sub-incurved, falcate, apex acute, puberulous; spur 4–8 × 1 mm, recurved, cylindrical, apex rounded; spurred sepal 24–35 mm long; remaining 4 smaller calyx lobes 1.5–2.5 × 2–3 mm, deltoid to ovate, apex obtuse. Petals absent. Stamen 1, filament 2–3 mm long, anther 16–19 mm long, densely villose on the back and between the thecae on the inner side; staminodes 2, 1– 1.5 mm long, glabrous. Ovary 2 × 1.5–2 mm, conical, tomentose; style 17–18 mm long, cylindrical but with the upper half slightly clavate, straight to incurved, glabrous except for the base; stigma capitate, terminal. Capsule and seeds unknown.

Distribution and habitat: —This species was collected in a forest border, in the southern part of the municipality of Altamira, Serra do Cachimbo, Pará state, Brazil ( Figure 3 ). This region, north of Mato Grosso state and south of Pará, is a transition area between Amazon rainforests and cerrados from Central Brazil ( MMA 2009).

Phenology: —The only known gathering was collected in flowers in December.

Conservation status: —The lack of additional collections of Vochysia sobralii prevents the assessment of extinction risk, rendering it as data deficient (DD) for now, following IUCN Red List guidelines ( IUCN Standards and Petitions Subcommittee 2016).

The species was collected during one of the flora surveys for the creation of the “Nascentes da Serra do Cachimbo” Biological Reserve, which is a conservation unit with significant environmental importance, as it protects hundreds of perennial springs, forming important rivers in the Xingu and Tapajós basins, and also because of its heterogeneity and environmental peculiarity ( MMA 2009). However, despite being a conservation unit, the region endures threats such as deforestation for grazing and fires, which were intensified in 2021 ( ISA 2021).

Etymology: —The specific epithet honors the plant taxonomist and Myrtaceae specialist Prof. Marcos Eduardo Guerra Sobral, who collected the species during the floristic survey for the “Nascentes da Serra do Cachimbo” Biological Reserve’s management plan ( MMA 2009).

Discussion: —Within Vochysia sect. Pachyantha , Vochysia sobralii is more similar to V. sofiae , due to the long petioles, large leaves, and cuspidate leaf apex. But it differs in the cuneate leaf base (vs. obtuse or rounded in V. sofiae ) and acute flower bud apex (vs. obtuse). Also, V. sobralii occurs in southern Pará, Brazil, ca. 1,500 km apart from Saint-Georges-de-l’Oyapock, French Guiana, where V. sofiae was collected. A dichotomous key and a link to a multi-access interactive key for all ten species of the section Pachyantha are presented below.

Figures

FIGURE 1. Vochysia sobralii. A. Flowering branch. B. Nodal region, showing stipules. C. Detail of the indument on the abaxial surface of the leaf. D. Flower in lateral view. E. Flower in front view. F. Stamen in front (left) and back (right) views. G. Gynoecium. H. Front view of flower after anthesis with the two frontal sepals and part of the hypanthium removed. I. Staminode. M. Sobral & A.G. Oliveira 10876. Drawn by Klei Sousa.

FIGURE 2. Vochysia sobralii. A. Habit. B. Inflorescences. C. Detail of the inflorescence with flower buds on top, flowers in anthesis on the central portion and older flowers showing just the ovaries on the proximal portion of the inflorescence. D. Detail of open flowers with showy fourth sepal and curved style. E. Flower buds showing acute apex and recurved spur. F. Detail of old flowers, showing just the tomentose ovaries. A–F. M. Sobral & A.G. Oliveira 10876. All photos by M. Sobral.

FIGURE 3. Geographic distribution of Vochysia sobralii (red star).