Myrcia guianensis (Aubl.) De Candolle (1828: 245)

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 : 48

24. Myrcia guianensis (Aubl.) De Candolle (1828: 245) .

Basionym:— Eugenia guianensis Aublet (1775: 506) .

Type:— BRITISH GUIANA. ‘Habitat in silvis propè montem Serpent dictum’, s.d., Aublet s.n. (holotype BM [000953654], image; isotype LINN [HS883-22]) . ( Figs. 5 G-H)

Trees or shrubs 3– 10 m. Twigs glabrous. Leaves with petioles 2–5 mm long, glabrous, channeled; blades elliptic, obovate, oval or oblong, 2.2–7.2 × 2–4 cm, glabrous, chartaceous or coriaceous, concolorous; glands conspicuous; base rounded or cuneate; apex acute, rounded or obtuse; midvein adaxially prominent or flat; lateral veins visible, not arched, 13 to 17 pairs; intra-marginal vein 1–2 mm from the margin, margin flat. Inflorescence terminal or subterminal, panicle or thyrsoid, flowers lax, the axis 4–6.1 cm long, puberulent, the indumentum brownish, the first branching 2.7–3.1 cm long; bracts lanceolate, 0.5 × 1 mm, glabrous, caducous after anthesis; pedicels 0.5–2 mm long, glabrous; bracteoles lanceolate, 0.5 × 1 mm, glabrous, caducous after anthesis; flower buds globose or obovate, 2 × 1 mm, not constricted above ovary; calyx-lobes free, five, orbicular, 0.5–1 × 1–2.5 mm, glabrous, not reflexed, persistent in the fruit; ovary 3-locular. Immature fruit globose, 0.4–0.7 × 0.5–0.6 cm, glabrous, smooth surface.

Note:— Myrcia guianensis may be recognized by its glabrous leaves, the globose or obovate flower buds, and the 3-locular ovary. This species is morphologically related to M. amazonica from which it is distinguished by its grayish branches (vs. reddish) an adaxially prominent or flat midvein (vs. impressed). It is also morphologically related to M. cuprea from which it is distinguished by its glabrous branches and globose or obovate flower buds (vs. pubescent branches and campanulate flower buds).

Distribution and habitat:— Bolivia, Colombia, Ecuador, French Guiana, Guyana, Panamá, Paraguay, Peru, Suriname, Trinidad-Tobago and Venezuela and widely distributed in Brazil (POWO 2020, Flora do Brasil 2020). In Amazonian Maranhão, Myrcia guianensis was found growing in “terra firme” and secondary forest.

Phenology:— Flowering in August to December and fruiting in October.

Specimens examined:— BRAZIL. Maranhão: Old capoeira on hillside W. of road, appr. 45km. S. of Itauna on road from Pinheiro , 2°27’ S, 44°49’59” W, 18 October 1980 (fl., fr), D.C. Daly & D.G. Campbell 686 ( IAN!) . São Luis, Alumar , 2°41’30” S, 44°19’44” W, 13 November 1995 (fl.), K.B. Ferreira & E. Girnos s.n. ( MAR!) . Pinheiro, Nova Esperança, Rio Alto Turiaçu , 100 m, 2°55’12” S, 45°45’ W, 04 December 1978 (fl.), J. Jangoux 199 & R.P . Bahia ( NY!) .

Additional specimens examined:— BRAZIL. Pará : Santarém , along E side of road to Punta Piedra , about 3.4 km from where the road departs to the NW from the Santarém–Alter do Chão road (PA-457), ca. 21.5 km E and somewhat S of Santarém, 73 m, 2°30’17” S, 54°53’04” W, 24 November 2011 (fr.), B.M. Torke 1292 ( NY!); Oriximinã, Porto Trombetas. Mineração Rio do Norte, Mina Saracá, 1°42’ S, 56°27’ W, 1999 (fl.), E.M. Barbosa 324 (INPA, 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.