Psidium acutangulum De Candolle (1828: 233)

Amorim, Gabriela Dos Santos, Barbosa, Maria Regina De Vasconcellos, Jr, Eduardo Bezerra De Almeida & Thomas, William Wayt, 2022, Taxonomic study of Myrtaceae in forest fragments in Amazonian Maranhão, Brazil, Phytotaxa 568 (1), pp. 27-60 : 56

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!) .

Figures

FIGURE 6. A-B. Myrcia minutiflora. A. Habit. B. Fruit. C–E. Myrcia neoclusiifolia. C. Habit. D. Inflorescence in panicle. E. Fruit. F–G. Myrcia neospeciosa. F. Habit. G. Fruit. H–J. Psidium acutangulum. H. Habit. I. Inflorescence in dichasia. J. Fruit.