Myrciaria evanida Sobral 2013, sp. nov.
Creators: name: Sobral, Marcos
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Myrtales
Myrtaceae
Myrciaria
Myrciaria evanida

description: 1.8. Myrciaria evanida Sobral, sp. nov.
Type: BRAZIL. Espírito Santo: Reserva Florestal de Sooretama, 2 Aug. 1969, D. Sucre 5459 (holotype RB; isotype BHCB).
Figure 8.
This species resembles Myrciaria floribunda, from which it differs through the vanishing secondary veins and smaller flowers.
Tree to 6 m. Twigs grey, with simple grey trichomes 0.2–0.3 mm, curled upwards, the internodes 15–25 × 1– 1.5 mm, sometimes their bases bearing four to six series of imbricate cataphylls, the proximal ones triangular, to 1 × 1 mm, and the distal ones linear, to 6 × 1.5 mm. Leaves with petioles glabrous or with trichomes as the twigs, canaliculate, 4–10 × 0.8–1 mm; blades lanceolate, oblong or ovate–oblong, 55–130 × 18–47 mm, 2.3– 3.3 times longer than wide, concolorous or slightly discolorous, brown or olive green when dried, glabrous except for the midvein; glandular dots visible only against light, smaller than 0.05 mm in diameter and 20–25 per square milimeter; apex acuminate and mucronate; base widely cuneate; midvein sulcate and densely covered with grey simple trichomes to 0.3 mm adaxially, prominent and with trichomes to 0.3 mm abaxially; lateral veins 15 to 20 at each side, ascendent, leaving the midvein at angles of about 70 degrees, adaxially sulcate along half of its length and then markedly diminishing in gauge, becoming plane and apparently vanishing distally, abaxially prominent along about half of its length and then also becoming plane and vanishing, occasionally with scattered trichomes as the midvein; marginal vein 0.5–1 mm from the margin. Inflorescences glomerulate, mostly ramiflorous, sometimes axillary, with up to four sessile flowers; bracteoles sometimes fused when young, widely triangular, glabrous, to 1 × 1 mm; flower buds globose, to 1.5 mm in diameter; calyx glabrous, with four lobes, more or less unequal between them, the external ones hemispherical, to 0.4 × 0.8 mm, the internal ones ovate to elliptic, to 0.8 × 1.5 mm; petals spathulate, 1–1.5 × 0.9–1 mm, with some glands and cilia up to 0.1 mm; stamens about 50, to 4 mm long, the anthers elliptic, to 0.3 × 0.1–0.2 mm, eglandular; staminal ring 0.8–1 mm wide; calyx tube 0.2–0.3 mm deep, deciduous after anthesis; style to 5 mm, with scattered simple trichomes to 0.1 mm along the proximal half, the stigma slightly capitate and papillose; ovary with two locules and two or sometimes three centrally attached ovules per locule. Fruits (immature) globose, to 10 mm in diameter.
Distribution, habitat and phenology:— Myrciaria evanida was gathered at two localities in southeastern Brazil, the Sooretama Federal Reserve in the state of Espírito Santo and the Rio Doce State Park in the state of Minas Gerais, both in the Atlantic Rainforest domain. The two sites are 500 km apart, but both are along the Rio Doce basin; so, it is possible that in the future the species may be collected in other sites along this basin, although this entire region has been subject to high levels of deforestation. Flowers were collected in August and fruits in July.
Conservation:—considering the large distance between the two collection sites and the scarcity of additional information, this species must be scored as DD (Data Deficient), according to IUCN criteria (IUCN 2001).
Affinities:—this species is apparently related to the widespread Myrciaria floribunda (H.West ex Willdenow) O.Berg (for descriptions see Willdenow 1799, Berg 1855–1856, McVaugh 1963 or Morais & Lombardi 2006), from which it differs through the characters in the couplet:
1. Leaves with secondary veins not diminishing in gauge along their course; mature flower buds at least 3 mm long .... .................................................................................................................................................... Myrciaria floribunda
—. Leaves with secondary veins visibly diminishing in gauge along their course, scarcely visibly at their distal part; mature flower buds about 1.5 mm long. .......................................................................................... Myrciaria evanida
Etymology:—the epithet is derived from the Latin word for "vanishing", alluding to the venation of this species.
Paratypes:— BRAZIL. Minas Gerais: mun. Marliéria, Parque Estadual do Rio Doce, Apr. 2006, A. Percina s.n. (BL 1 árvore 81, inventário florestal de MG) (BHCB); Parque Estadual do Rio Doce, trilha da Lagoa Preta, 15 Jul. 2000, L.G. Temponi & R.M. de Carvalho Okano 141 (VIC).
description: Published as part of Sobral, Marcos, 2013, Eight New Atlantic Rainforest Species and Nomenclatural Notes in Brazilian Myrtaceae, pp. 43-61 in Phytotaxa 135 (1) on pages 57-59, DOI: 10.11646/phytotaxa.135.1.6, http://zenodo.org/record/5086159