Myrciaria O. Berg

Sobral, Marcos, Grippa, Carlos R., Souza, Marcelo C., Aguiar, Osny T., Bertoncello, Ricardo & Guimarães, Thais B., 2012, Fourteen new species and two taxonomic notes on Brazilian Myrtaceae, Phytotaxa 50 (1), pp. 19-50 : 46-48

5. Myrciaria O. Berg

The genus Myrciaria O.Berg comprises 24 species ranging from Mexico and Antilles to Uruguay ( Govaerts et al. 2011), from which 20 are reported for Brazil. It is characterized mostly by the flowers with ovaries with two locules and two locules per ovule, as well as the deciduous calyx tube, which leaves a typical circular scar in the fruits.

5.1. Myrciaria alagoana Sobral , sp. nov. Type: Brazil, Alagoas, mun. São Miguel dos Campos, Engenho Novo, 4 Jan. 1968, M. T. Monteiro 21879 (holotype HST). Figure 14 .

This species is related to Myrciaria glomerata , differing through its glabrous and longly acuminate leaves.

Tree (?). Twigs grey, glabrous or with scattered simple grey or white trichomes to 1.5 mm, the internodes 15–25 × 1.5–2 mm. Leaves with petioles glabrous or with trichomes as the twigs, canaliculate, 5–7 × 1–1.2 mm; blades elliptic–caudate, 65–90 × 25–33 mm, 2.6–3.3 times longer than wide, concoloured or slightly discoloured when dried, glabrous or with scattered simple trichomes 1–1.5 mm along the midvein at the abaxial side; glandular dots visible only against light, smaller than 0.1 mm in diameter and about ten per square milimeter; apex caudate and mucronate in 13–20 mm; base cuneate; midvein sulcate adaxially and prominent abaxially; secondary veins 12 to 30 at each side, straight, leaving the midvein at angles about 70 degrees, weakly prominent adaxially and a little more so abaxially; marginal vein to 0.5 mm from the margin, the margin itself with a yellow thickening to 0.1 mm wide. Inflorescences glomerulate, axillary, with up to four sessile flowers; bracteoles fused at least when young, elliptic, to 2.7 × 2 mm, darker than the flower buds when dry, somewhat covered with grey trichomes to 0.3 mm; flower buds obovate, 5–6 × 3 mm, densely and uniformly covered with grey to white trichomes to 1 mm; calyx lobes four, more or less equal between them, ovate, 2 × 1.6–2 mm, pilose abaxially and glabrous adaxially; petals obovate, 2–2.5 × 1.8–2 mm, glabrous adaxially and moderately covered with brown or grey trichomes 0.2–0.3 abaxially; stamens about 100, to 4 mm long, the anthers elliptic, 0.2–0.4 × 0.2 mm, eglandular; staminal ring to 2 mm wide; calyx tube 1–1.5 mm deep, glabrous; style 4–5 mm, glabrous, the stigma punctiform and not visibly papillose; ovary with two locules and two ovules per locule. Fruits not seen.

Distribution, habitat, phenology — this species is known only from two collections gathered in 1968 in São Miguel dos Campos, in the northeastern coastal zone of the state of Alagoas. Flowers were collected in April and December.

Conservation status — there are about 1200 collections from São Miguel dos Campos ( CRIA 2012), a municipality of 360 km 2 ( IBGE 2012), rendering an average of about 3 collections / km 2; nevertheless, most of these collections are from more than thirty years ago and present information about the collection sites is wanting; so, although the two known collections of Myrciaria alagoana , as well as the absence of recent collections, may suggest its rarity, it must be scored as DD (Data Deficient) according to IUCN criteria (IUCN 2001)

Affinities — Myrciaria alagoana is apparently related to M. glomerata O.Berg (for description see Berg 1857 –1859: 365 or Morais & Lombardi 2006: 26), differing from it through the longly acuminate and abaxially glabrous leaves.

Etymology — the epithet is allusive to the collection place.

Vernacular name — araçá–mulato (according to the holotype label).

Paratype — Brazil, Alagoas, mun. São Miguel dos Campos, Fazenda Brasil, 18 Dec. 1968, M. T . Monteiro 23073 ( HST) .

Figures

FIGURE 14. Myrciaria alagoana — image of holotype (scale — 50 mm). Insert: inflorescence (scale — 10 mm).