Taxonomic study of Myrtaceae in forest fragments in Amazonian Maranhão, Brazil Author Amorim, Gabriela Dos Santos Programa de Pós-graduação em Biologia Vegetal, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego, 1235 - Cidade Universitária, 50670 - 901, Recife - PE, Brazil. Author Barbosa, Maria Regina De Vasconcellos Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba, Cidade Universitária, Caixa Postal 5065, 58051 - 970, João Pessoa- PB, Brazil. Author Jr, Eduardo Bezerra De Almeida Departamento de Biologia, Universidade Federal do Maranhão, Cidade Universitária Dom Delgado, Av. dos Portugueses, 1966 - Vila Bacanga, 65080 - 805, São Luís - MA. Author Thomas, William Wayt 0000-0002-4996-536X Institute of Systematic Botany, New York Botanical Garden, 2900 Southern Boulevard, Bronx, 10458 - 5126, NY, United States. wthomas @ nybg. org; https: // orcid. org / 0000 - 0002 - 4996 - 536 X wthomas@nybg.org text Phytotaxa 2022 2022-10-11 568 1 27 60 http://dx.doi.org/10.11646/phytotaxa.568.1.3 journal article 10.11646/phytotaxa.568.1.3 87ddb879-1616-4e3b-8817-434b61fb0c60 1179-3163 7184245 36. Psidium acutangulum De Candolle (1828: 233) . Type:— BRAZIL . “ Provinciae Rio Negro ”, C.F.P. Martius 2931 ( holotype : M [0032369]) . ( Fig. 6 H-J) Shrubs ca. 2 m . Twigs glabrous. Leaves with petioles 0.5–1 mm long, densely pubescent, unchanneled; blades elliptic to broadly so, 3.9–6 × 2.9–3 cm , glabrous, membranaceous or chartaceous, discolorous; glands conspicuous; base attenuate or rounded; apex acute, apiculate; midvein adaxially sulcate; lateral veins visible, arched, 5 to 7 pairs; intramarginal vein absent, margin flat. Inflorescence axillary, a solitary flower, dichasia, or rarely an auxotelic raceme, the axis inconspicuous, glabrous; bracts not seen, caducous before anthesis; pedicels 2.1–5.3 mm long; bracteoles not seen, caducous before anthesis; flower buds globose, apiculate, 4–9 × 6–7 mm , constricted above ovary; calyx-lobes completely fused, four to five, opening by irregular tearing, glabrous, ovate, 0.5 × 0.5 mm , not reflexed, persisting in the fruit; ovary not seen. Immature fruit globose, 1–2 × 1.5–2.3 cm , glabrous, surface marked with glands. Note:— Psidium acutangulum may be recognized by its glabrous, elliptic to broadly elliptic leaves with an apiculate leaf apex; a solitary flower, or sometimes with an auxotelic raceme; the four to five calyx-lobes opening by irregular tearing; and the globose fruits which are glabrous and have the surface marked with glands. Distribution and habitat:— Known from Bolivia , Colombia , Ecuador , French Guiana , Guyana , Peru , Suriname , Venezuela and central, northeastern and northwestern Brazil ( Acre , Amazonas, Amapá , Maranhão , Mato Grosso , Pará, Rondônia , Roraima , and Tocantins states) (POWO 2020, Flora do Brasil 2020 ). In Amazonian Maranhão , P . acutangulum was found growing in flooded forest and along rivers. Phenology:— Flowering in February and October and fruiting in November. Specimens examined:— BRAZIL . Maranhão : Maracassumé River Region , 08 October 1932 (fl.), R.L. Fróes 1927 ( NY !) . Monção , Urutawy , Ka’ apor Indian Reserve , basin of Rio Turiaçu , 05 November 1986 (fl), W.L Balée & B.G. Ribeiro 2904 ( MG !) . Pinheiro , Rio Alto Turiaçu , Nova Esperança , 100 m , 2°55’12” S , 45°45’ W , 29 November 1978 (fr.), J. Jangoux 78 & R.P . Bahia ( NY !) . São Luis , Alumar , 2°31’47” S , 44°18’10” W , 20 February 1985 (fl.), M. Salgado & R.M.G. Cardoso 69 ( IAN !) . Additional specimens examined:— BRAZIL . Acre : Sena Madureira , Riozinho do Andirá , colocaçao Curitiba , 9°43’45” S , 68°08’53” W , 10 June 1995 (fl.), A.R.S. de Oliveira 572 ( NY !) . Pará. Oriximiná, Rio Paru do Oeste , Cachoeira Chuvisco , 0°59’58” S , 56°04’42” W , 07 November 1980 (fl.), C.A.C. Ferreira 2247 ( NY !) .