Three new species of Eugenia sect. Racemosae (Myrtaceae) from the cerrados of the state of Mato Grosso, Brazil

Três espécies novas de Eugenia sect. Racemosae (Myrtaceae) dos cerrados do Estado do Mato Grosso, Brasil

REVIEW PAPER

Three new species of Eugenia sect. Racemosae (Myrtaceae) from the cerrados of the state of Mato Grosso, Brazil

Três espécies novas de Eugenia sect. Racemosae (Myrtaceae) dos cerrados do Estado do Mato Grosso, Brasil

Fiorella Fernanda Mazine^I,1; Vinicius Castro Souza^II

^IUniversidade Federal de São Carlos, câmpus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, 18052-780 Sorocaba, SP, Brazil

^IIUniversidade de São Paulo, Escola Superior de Agricultura "Luiz de Queiroz", Departamento de Ciências Biológicas, Caixa Postal 9, 13418-900 Piracicaba, SP, Brazil.

ABSTRACT

Three new species of Eugenia sect. Racemosae (Myrtaceae) from cerrado vegetation of central region in Brazil are described and illustrated. They are: Eugenia hatschbachii Mazine, Eugenia mattogrossensis Mazine and Eugenia glabrescens Mazine. Data on the geographic distribution and habitat are given for the new taxa.

Key words: Brazil, Eugenia, Myrtaceae, taxonomy

RESUMO

Três espécies novas de Eugenia sect. Racemosae (Myrtaceae) dos cerrados da região central do Brasil são descritas e ilustradas. São elas: Eugenia hatschbachii Mazine, Eugenia mattogrossensis Mazine e Eugenia glabrescens Mazine. São fornecidos dados de distribuição geográfica e hábitat de cada um dos táxons.

Palavras-chave: Brasil, Eugenia, Myrtaceae, taxonomia

Introduction

As referred by Holst (2002), Eugenia is one of the neotropical genera of Myrtaceae most in need of study, as Myrcia is. Because of their large sizes, no one has attempted to treat them as a whole since the major publications of Berg (1856, 1857, 1858a, 1858b, 1859, 1860, 1861).

The largest of the New World Myrtaceae genera, Eugenia L. is currently estimated to contain 500 (Holst et al. 2003) to 2,000 species (Sanchez-Vindas et al. 2001), distributed from South of Mexico, Cuba, the Antilles to Uruguay and Argentina, with a small number of species (ca. 60) in Africa (Merwe et al. 2005).

The species of Eugenia have been classified by Berg (1856) into sections based on inflorescence morphology. According to Mazine (2006), Eugenia sect. Racemosae O. Berg is a phylogenetically consistent group, diagnosed by its flowers exclusively in racemes and/or panicles, with a distinctive axis bearing the flowers along with a proportion pedicel × internode of 2×1 ratio or less. During the preparation of a monograph of the Brazilian species of Eugenia sect. Racemosae O. Berg, several new species were found. Descriptions of three new species of Eugenia sect. Racemosae from the cerrado region of central Brazil are presented here. Distribution data, illustrations as well as comments on all species are also presented.

Results and discussion

Eugenia hatschbachii Mazine, sp. nov. Type: BRAZIL. Mato Grosso: Barra do Bugres, fazenda Ochsenfeld, 23-X-1995, G. Hatschbach, A.V. Pott & E. Barbosa 63773 (holotype MBM).

Figure 1

Racemi multiflori, rhachidi glabra, hypanthio glabro, bracteae florales caducae. Ab Eugenia glabrescenti Mazine alabastro c. 2 mm diam. (nec 3-3.5 mm) et pedicelo 1-2.5 mm (nec 5-9 mm) differt.

Tree ca. 5 m; branches glabrous. Leaf blade oblong-lanceolate, 6-8.5 cm long, 1.6-2.3 cm wide, chartaceous, glabrous on the upper surface, glabrous to subglabrous on the lower surface, hairs simple; apex acute-acuminate; base acute; midvein sulcate on the upper surface; lateral veins slightly prominent, marginal vein ca. 1.5 mm from the margin; glandular dots slightly prominent on the upper surface; petiole 4-6 mm long. Raceme with 6-10 pairs of flowers, axillary or extra-axillary, peduncled to subsessile, peduncle 0-2 mm long; rachis 2-3 cm long, glabrous. Flower bud ca. 2 mm diam.; floral bracts deciduous, ca. 1 mm long; pedicel 1-2.5 mm, glabrous; bracteoles ca. 0.5 mm, persistent, free (not connate on the base), apex acute, glabrous with margin ciliate; sepals ca. 1 mm long, apex acute, glabrous, ciliate, persistent; petals 2-5 mm long, orbicular, apex rounded; filaments ca. 2 mm long, glabrous; hypanthium glabrous, surface smooth, style ca. 2 mm long, glabrous. Fruit not observed.

Etymology – the specific epithet honors Dr. Gerdt Hatschbach, Brazilian botanist who collected the type.

Known only from the type collection (cerrado of the region of Barra do Bugres in the State of Mato Grosso, Brazil), Eugenia hatschbachii is morphologically related to the group of species characterized by deciduous floral bracts, group where Eugenia aeruginea DC. and E. brownsbergii Amsh., for example, are also circunscribed. Eugenia hatschbachii has pluriflorous inflorescences, with glabrous rachis and flowers with glabrous hypanthium. The flowers are very small, the floral bud is ca. 2 mm in diameter, which can be used to distinguish it of Eugenia glabrescens (also described in this paper), in addition to the very short pedicel.

Eugenia mattogrossensis Mazine, sp. nov. Type: BRAZIL. Mato Grosso: Cláudia, perímetro urbano, 09-XI-1996, G. Árbocz 3167-A (holotype ESA).

Figure 2

Frutex vel suffrutex, flores dispositi in racemis axillaribus et apicalibus, vel in paniculis racemorum, rhachis racemi et hypanthium dense puberulum (velveto simile), bracteae florales ca. 3 mm longae, alabastra 4-5 mm diam., globosa, pedicelli 2.5-3.5 mm longi. Ab Eugenia polystachya Mazine bracteis floralibus caducis differt.

Subshrub to shrub 0.7-1.8 m; branches puberulous. Leaf blade elliptic, 12.5-16.8 cm long, 5.1-8 cm wide, chartaceous, subglabrous to puberulous on both surfaces, hairs simple; apex acuminate; base acute or obtuse-rounded; midvein sulcate on the upper surface; lateral veins flat to slightly prominent, marginal vein 3-4 mm from the margin; glandular dots indistinct or prominent; petiole 5-7 mm long. Racemes and/or panicle of racemes, with 7-15 pairs of flowers, axillary, peduncled or sessile, peduncle 0-7 mm long; rachis 5-11.4 cm long, densely puberulous, hairs whitish. Flower bud 4-5 mm diam.; floral bracts deciduous at the floral bud, ca. 3 mm long; pedicel 2.5-3.5 mm, densely puberulous; bracteoles ca. 1 mm long, connate on the basis, apex obtuse or rounded, sparsely puberulous, margin ciliate, persistent; sepals ca. 2 mm long, apex rounded, sparsely puberulous, margin ciliate, persistent; petals 3-5 mm long, apex rounded; filaments 4-5 mm long, glabrous; hypanthium densely puberulous, smooth, style ca. 10 mm long, glabrous. Fruit not observed.

Paratypes: BRASIL. Mato Grosso: Cuiabá, Chapada dos Guimarães, margem do rio Coxipozinho, perto da rodovia, 15º30' S 55º45' W, 21-X-1985, J. Pirani 1343 (K, MG, SPF). Cristianópolis, rodovia MT 339, 18 km de Cristianópolis para Tangará da Serra, 25-X-1995, G. Hatschbach, A.V. Pott & E. Barbosa 63883 (MBM).

Eugenia mattogrossensis is a shrub from Mato Grosso state, with flowers that can be arranged in simple racemes or panicles of racemes. The indumentum of the rachis and hypanthium of this species is densely puberulous and similar to velvet, its racemes are long, always axillary and on the top of the branches. It has also very short pedicels and large, globose flower buds. The floral bracts are large and early deciduous, falling before anthesis.

Eugenia glabrescens Mazine, sp. nov. Type: BRAZIL. Mato Grosso: Serra do Roncador, road Nova Xavantina to Barra do Garças, 55 km north of Barra do Garças, 15-X-1964, G.T. Prance & N.T. Silva 59428 (holotype RB, isotypes F, K, UB).

Figure 3

Folia glabra ad subglabra, racemi axibus tenuibus et filiformibus, hypanthium subglabrum. Eugeniae egensis DC. affinis, sed racemis rachidi 2.5-4.5 cm longa (nec brevi, rachidi 0,2-1,5 cm longa), bracteis floralibus caducis (nec persistentibus) distincta.

Tree ca. 6 m, branches densely pubescent. Leaf blade elliptic-lanceolate, 8.7-11 cm long, 2.3-2.8 cm wide, chartaceous, glabrous to subglabrous on both surfaces, hairs simple and dibrachiate, apex acuminate, base acute, midvein sulcate, subglabrous to very sparsely pubescent in both surfaces, lateral veins proeminent, marginal vein ca. 1.5 mm from the margin; glandular dots indistinct on the upper surface; petiole 5-7 mm long. Raceme with 7-11 pairs of flowers, axillary or extra-axillary, subsessile, peduncle 1-3 mm long, rachis 2.5-4.5 cm long, sparse to densely pubescent, hairs whitish. Flower bud 3-3.5 mm diam., floral bracts deciduous, 1.5 mm long, pedicel 5-9 mm long, sparse to densely pubescent, bracteoles ca. 1 mm long, free (not connate on the base), apex acute, subglabrous, ciliate, persistent, sepals ca. 1 mm long, apex acute or rounded, subglabrous, ciliate, persistent; petals ca. 4 mm long, orbicular, apex obtuse-rounded; filaments 3-4 mm long, subglabrous; hypanthium subglabrous, style 3-4 mm long, subglabrous. Fruit not observed.

Eugenia glabrescens is known only from the type collection (Serra do Roncador, Mato Grosso State). The leaves and flowers with a subglabrous hypanthium of Eugenia glabrescens are similar to those of Eugenia egensis DC., from Central America to Northeastern Argentina (Govaerts et al. 2008). However, E. egensis is not part of Eugenia sect. Racemosae. Furthermore, Eugenia glabrescens has deciduous bracts, while the bracts of E. egensis are persistent. The racemes of Eugenia glabrescens are longer and have delicate, filiform axis.

Acknowledgments – The authors express sincere appreciation to the following individuals: Maria Alice Rezende, for her care in preparing the plates here presented; the reviewers, for the helpful comments and valuable suggestions; Marcos Sobral and Eve Lucas for the discussions about the species; Cássio van den Berg, for correcting the Latin diagnoses. Fapesp, IAPT and KLARF are gratefully acknowledged for providing support during the development of the activities in Piracicaba-SP and at the Royal Botanic Gardens Kew.

(received: May 03, 2007; accepted: March 29, 2010)

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Publication Dates

• Publication in this collection
  01 Sept 2010
• Date of issue
  June 2010

History

• Accepted
  29 Mar 2010
• Received
  03 May 2007