Myrcia amazonica De Candolle (1828: 250)

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 : 43-45

18. Myrcia amazonica De Candolle (1828: 250) .

Type:— BRAZIL. Amazonas: Solimoes , s.d., C.F.P. Martius s.n. (lectotype designated by McVaugh 1969 [p. 110]: M). ( Fig. 5A .)

Tree or shrubs 2– 10 m. Twigs glabrous or sparsely pubescent, the indumentum brownish, the branches and inflorescence reddish. Leaves with petioles 2–4 mm long, pubescent, channeled; blades elliptic, lanceolate or ovate, 3.7–6.7 × 1.9–3.2 cm, glabrous, chartaceous, discolorous; glands conspicuous adaxially and strongly marked; base cuneate or rounded; apex acute or acuminate, rarely cuspidate; midvein adaxially impressed of flat; lateral veins visible, not arched, 8 to 12 pairs; intra-marginal vein 1–2 mm from the margin, margin flat. Inflorescence terminal or subterminal, panicle, pyramidal, flowers lax, the axis 7.8–13.8 cm long, glabrous, the first branching 4.2–6.8 cm long; bracts linear, ca. 2 mm, caducous before anthesis, pubescent; pedicels 1–3 mm long or absent, sparsely pubescent; bracteoles lanceolate or linear, 0.7–2 × 0.2 mm, caducous before anthesis, glabrous or sparsely pubescent; flower buds obovate, 2 x 1.5 mm, not constricted above ovary; calyx-lobes free, five, orbicular, 0.5 × 1 mm, glabrous, not reflexed, persistent in the fruit; ovary 2–locular. Immature fruit globose, 0.5 cm diameter, glabrous, surface smooth.

Note:— Myrcia amazonica may be recognized by its reddish branchlets and inflorescence, and its pyramidal panicle with small lax buds. This species is morphologically similar to M. guianensis from which it is distinguished by its reddish branches and inflorescences (vs. grayish), leaves with an adaxially impressed or flat midvein (vs. prominent) and 2-locular ovary (vs. 3-locular).

Distribution and habitat:— Known from south Central America, Bolivia, Brazil, French Guiana, Suriname and Venezuela. In Brazil it is widely distributed (POWO 2020, Flora do Brasil 2020). In Amazonian Maranhão, M. amazonica was found growing in “terra firme” and secondary forests.

Phenology:— Flowering from May to August and fruiting in August.

Specimens examined:— BRAZIL. Maranhão: São José de Ribamar, Sítio Aguahy , 2°38’51” S, 44°08’04” W, 28 August 2017 (fr.), G.S. Amorim 374 ( MAR!) . São Luís, Granja Barreto , 2°31’47” S, 44°18’10” W, 12 May 1950 (fl.), R.L. Fróes 24260 ( IAN!) ; Reserva Florestal do Sacavem [Mata da Caema], 2°34’04” S, 44°15’44” W, 1958 (fl.), J. Ferreira et al. 58 ( MAR!) ; 2°31’47” S, 44°18’10” W, 01 July 1992 (fl.), G.M. Barroso 61 (UEC, image); 27 May 1992 (fl.), F.H. Muniz 103 (RB, image); 2°30’ S, 44°15’ W, 14 August 1992 (fl.), F.H. Muniz 26 (INPA, image); 2°30’ S, 44°15’ W, 26 June 1993 (fl.), F.H. Muniz 392 (INPA, image); 2°31’47” S, 44°18’10” W, 28 June 1993 (fl.), F.H. Muniz 378 (INPA, image) . Turiaçu , 1°39’48” S, 45°22’18” W, Fazenda Vila Palmares, 23 July 1977 (fl.), A.E. Silva 131 ( PEUFR!) .

Additional specimens examined:— BRAZIL. Amazonas: Manaus, Igarapé do Passarinho , 2°57’ S, 60°02’50” W, 21 August 1956 (fl.), D.F. Coêlho INPA4109 (INPA, image). Pará: Santarém, Comunidade São Brás, 2°30’46” S, 54°51’33” W, 12 October 2012 (fl.), V.Y.P. Calao s.n. (INPA, image). Rondônia: Porto Velho, Jaci-Paraná, 8°45’43” S, 63°54’14” W, 13 July 2008 (fl.), G. Pereira-Silva 13547 (RON, image); Fragmento de floresta próximo a margem direita do, Floresta estacional semidecidual com relevo plano e afloramento rochoso, 9°16’19” S, 64°23’37” W, 26 June 2012 (fl.), M.F. Simon 1557 (RON, image) .

Figures

FIGURE 5. A. Fruits in Myrcia amazonica. B. Flowers in Myrcia bracteata. C–D. Flowers and fruits in Myrcia cuprea. E–F. Flowers and immature fruits in M. eximia. G–H. Flowers in Myrcia guianensis. I–J. Flowers bud and immature fruits in Myrcia multiflora. K–L. Flowers bud and immature fruits in Myrcia selloi. M–N. Flowers and fruits in Myrcia splendens. O. Flowers in Myrciaria tenella. P. Fruit in Psidium guineense.