Eugenia zigzag K. Coutinho & Sobral 2018, sp. nov.
Creators: name: Sobral, Marcos
name: Faria, Jair E. Q.
name: Coutinho, Karoline
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Myrtaceae
Eugenia
Eugenia zigzag

description: 5. Eugenia zigzag K.Coutinho & Sobral, sp. nov.
Type:— BRAZIL. Bahia: [Livramento de Nossa Senhora] Livramento do Brumado, ca. 6 km W da estrada Livramento para Brumado, entrando ca. 13, 4 km S de Livramento, 13°47’17” S, 41°50’04” W, 15 June 2002, L.P. de Queiroz, E.R. de Souza, J.G. Jardim, J.G. Sobrinho & B.M. Silva 7053 (holotype HUEFS!; isotype HUFSJ!). Figure 5.
Diagnosis:—This species is distinct from all Brazilian species of the genus by its branches with a zig-zag pattern.
Description:—Tree 3.5– 5 m. Twigs glabrous or with scattered simple trichomes 0.3–0.5 mm, grey when dry, very tortuose, irregularly branching in zig-zag pattern, sometimes additionally to this pattern also diverging dichotomously, minutely longitudinally striate, the internodes 2–15 × 2–3 mm, sometimes with cataphylls 0.8–1.5 × 1 mm in 3 to 4 series at its base, coeval with leaves, usually with two or more linear hyaline colleters to 0.7 × 0.1 mm at the junction with the leaves. Leaves mostly at the tips of the twigs; petioles adaxially applanate, glabrous, 1.5–4 × 0.7–1 mm; blades glabrous, widely ovate or nearly orbicular, 25–42 × 15–28 mm, 1.3–1.8 times longer than wide, markedly discolorous when dry, dull dark brown adaxially and dull green abaxially; glandular dots about 20/mm², about 0.1 mm in diameter, scarcely visible adaxially and evident abaxially; apex obtuse; base rounded, sometimes slightly decurrent at the junction with the petiole; midvein sulcate adaxially, sometimes scarcely so, moderately raised and darker than the surface abaxially; lateral veins 5 to 9 at each side, scarcely visible adaxially, visible and sometimes slightly raised abaxially, leaving the midvein at angles about 45°; marginal vein discontinuous, formed by the arches of the lateral veins, 1–2 mm from the margin, sometimes a second marginal vein to 0.3 mm from the plane margin. Inflorescences auxotelic, at the base of twigs, composed of two flowers opposite to each other and then the twig originating leaves; bracts to 1.5 × 1 mm, with simple trichomes to 0.2 mm; pedicels 13–15 × 0.2–0.4 mm, glabrous; bracteoles not seen, probably deciduous before anthesis (although scars were not observed); flower buds not seen; calyx lobes four, elliptic or elliptic-oblong, about the same size, 3–4 × 1–2 mm, markedly reflexed at anthesis, glabrous; petals obovate or spathulate, glabrous, to 6 × 3 mm; stamens about 80, to 7 mm, the anthers oblong, to 0.5 × 0.2, eglandular; staminal ring glabrous, subquadrate, 2 mm wide; calyx tube absent; style to 7 mm, the stigma slightly capitate and papillose; ovary glabrous externally and internally, with two locules and 3 to 4 ovules per locule. Fruits globose, immature, 13–15 mm in diameter; seed one, immature and not examined.
Distribution, habitat and phenology:— Eugenia zigzag is presently known only from the municipality of Livramento de Nossa Senhora (“Livramento do Brumado”), in central Bahia, where it grows in dry forests (“caatinga”); flowers and fruits were collected in June.
Conservation:—The two known collections of this species are from the municipality of Livramento de Nossa Senhora, with an area of 1953 km ² (IBGE 2016) from where there are known about 1,000 collections (INCT 2016), resulting in a weak sampling effort of about 0.5 collection/km²; considering this and the absence of additional information about the habitat of the species, it seems adequate to score it as DD (Data Deficient) according to IUCN conservation criteria (IUCN 2001).
Affinities:—This species is very distinct from all other Brazilian Eugenia by its zigzag branching. Due to its auxotelic inflorescences, long calyx lobes that are markedly reflexed after anthesis and the possibly deciduous bracteoles, Eugenia zigzag probably belongs to section Eugenia, according to the phylogenetic scheme proposed by Mazine et al. (2016).
Etymology:—The epithet is allusive to the characteristic branching pattern of the species.
Paratype:— BRAZIL. Bahia: [Livramento de Nossa Senhora] Livramento do Brumado, ca. 6 km W da estrada Livramento para Brumado, entrando ca. 13.4 km S de Livramento, 13°47’17” S, 41°50’04” W, 15 June 2002, L.P. de Queiroz, E.R. de Souza, J.G. Jardim, J.G. Sobrinho & B.M. Silva 7067 (HUEFS!, HUFSJ!).
description: Published as part of Sobral, Marcos, Faria, Jair E. Q. & Coutinho, Karoline, 2018, Five new Brazilian species of Eugenia (Myrtaceae), pp. 59-70 in Phytotaxa 347 (1) on pages 67-69, DOI: 10.11646/phytotaxa.347.1.3, http://zenodo.org/record/13707869