The Ocotea aureotomentosa (Lauraceae) hypothesis

The Ocotea aureotomentosa (Lauraceae) hypothesis based on the morphological line of evidence LEANDRO C. S. ASSIS, CAROLINE C. A. SILVA,

AND IONE

S. H. SALIM

Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil; e-mail: [email protected]; [email protected]

Abstract. A new species of Ocotea (Lauraceae), O. aureotomentosa, is hypothesized and illustrated. We follow K. de Queiroz’s view of a unified species concept and use morphological evidence to support our species hypothesis. Keywords: Brazilian Atlantic forest, Espinhaço Range, Lauraceae, Minas Gerais, biodiversity knowledge.

Ocotea Aubl., the largest genus of Lauraceae in the New World, comprises ca. 400 species in this region (van der Werff, 2017) plus ca. 50 to 60 species in Africa and Madagascar (Rohwer, 1993; Madriñán, 2004). The genus is highly diversified in the lowlands and montane forests (Rohwer 1986, 1993). Molecular phylogenetic analyses based on sequences of trnL-trnF and psbA-trnH chloroplast DNA, and ITS/5.8 region of nrDNA (Chanderbali et al., 2001) strongly suggest that the genus is polyphyletic, but a new classification that expresses the phylogenetic relationships has not yet been proposed. Therefore, Ocotea is not taxonomically well defined, although its species have been characterized by stamens with four pollen sacs arranged in two horizontal pairs and both tepals and anthers usually not covered with papillae (Rohwer, 1986; van der Werff, 1991). In this article, we hypothesize a new hermaphrodite species of Lauraceae from the Brazilian Atlantic Forest Oliveira-Filho & Fontes (2000). We follow de Queiroz’s (2007: 879) view of a unified species concept, which Bcan be achieved by treating existence as a separately evolving metapopulation lineage as the only necessary property of species and the former secondary species criteria as different lines of evidence (operational criteria) relevant to assessing lineage separation.^ Accordingly, the morphological line of evidence, on the basis of a unique combination of features shared by the specimens analyzed here, supports our species hypothesis. Terminology of vegetative and reproductive morphology follows Radford et al. (1974),

Weberling (1992), and Rohwer (1993). Flowers of Ocotea are composed of two whorls of tepals; three whorls of stamens (each one with three elements); a fourth innermost whorl of staminodia (with three elements or sometimes absent); and a unicarpelar gynoecium. The description of flower length includes the pedicel. Specimens from the B, BHCB, HBG, K, MBM, MO, NY, OUPR, P, RB, and SPF herbaria (Thiers, 2017) were analyzed with a stereoscope Zeiss Stemi DV4. Ocotea aureotomentosa L. C. S. Assis, sp. nov. Type: Brazil. Minas Gerais: Mariana, 20°10'37"S, 43°26'51"W, 26 Jun 2015 [fl] M. Mendes 3 (holotype: BHCB; isotypes: K, MO, RB). (Fig. 1). Diagnosis: Ocotea aureotomentosa resembles Ocotea aciphylla (Nees & Mart.) Mez, but differs by having the branches and leaves covered by curled hairs (vs. straight hairs), the leaf base flat (vs. revolute), and domatia frequently present (vs. absent) in the axils where the secondary veins attach to the primary vein on the abaxial leaf surface.

Trees 11–14 m tall. Branches with continuous growth, rounded to sulcate, surface of young branches totally covered by golden, curled, and appressed to erect hairs, surface of older branches glabrescent, sparsely lenticelate. Leaves alternate; petioles (0.5–)0.8–1.2 cm long, sulcate; blades (2.2–)3.9– 11.5 × (0.7–)1.1–3.2 cm, elliptic to narrowly elliptic, base acute, apex caudate, rarely acuminate, both surfaces partially covered by golden, curled and appressed to erect hairs, these totally covering the adaxial surface in young

Brittonia 70(3): 312Y315 (2018), DOI 10.1007/s12228-018-9528-2 ISSN: 0007-196X (print) ISSN: 1938-436X (electronic) © 2018, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A. Published Online: 14 May 2018

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FIG. 1. Ocotea aureotomentosa. A. Flowering branch. B. Leaf, abaxial surface view. C. Detail of the abaxial surface, showing the indument on primary and secondary veins and lamina. D. Flower apical view. E. Adaxial surface of a tepal of the outer whorl. F. Adaxial surface of a tepal of the inner whorl. G. Adaxial surface of a stamen of the first whorl I. H. Adaxial surface of a stamen of the second whorl. I. Abaxial surface of a stamen of the third whorl, with a pair of irregular glands at the base. J. Adaxial surface of a staminodium of the forth whorl. K. Pistil. (A-K from Mendes 3, BHCB). Drawings from Bárbara Rossi.

leaves, primary vein prominent and conspicuous on both surfaces, secondary veins level to slightly raised and inconspicuous on the adaxial surface,

prominent and conspicuous on the abaxial surface, brochidodromous, forming 15–30° angles with primary vein, domatia absent or present,

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comprising shallow holes in the axils where the secondary veins attach to the primary vein, covered by the indument. Cataphylls absent or present. Inflorescences (1.5–)2–6.4 cm long, botryoid to thyrsoid, totally covered by golden, curled, and appressed to erect hairs. Flowers 5.5– 6.5 mm × 2–2.5 mm; pedicels 2–3 mm long; hypanthium ca. 2 mm × ca. 1.5 mm, obconic, outer surface partially to totally covered by golden, slightly curled, and appressed to erect hairs, inner surface partially covered by golden, straight and appressed hairs; tepals 1.5–1.8 mm × 1–1.2 mm, elliptic, oblong, ovate or obovate, the adaxial surface partially to totally covered by golden, curled, and appressed to erect hairs, and the abaxial surface partially to totally covered by golden, curled, and appressed to erect hairs in the proximal portion, and with papillae partially covering the distal portion and margins; stamens of first whorl 1.2–1.3 mm long, filaments 0.4– 0.5 mm long, anthers 0.7–0.8 mm long, ovate, apex acute to obtuse, both lower and upper pairs of pollen sacs introrse, stamens of second whorl 1.3–1.4 mm long, filaments 0.6–0.8 mm long, anthers 0.7–0.8 mm long, oblong to ovate, apex acute, the lower pair of pollen sacs introrse to latrorse, the upper pair introrse, stamens of third whorl 1.3–1.5 mm long, filaments 0.7–1 mm long, anthers 0.5–0.8 mm long, oblong, apex acute to obtuse, both lower and upper pairs of pollen sacs introrse to latrorse, filaments of the three fertile whorls partially covered by golden, curled, and appressed to erect hairs, anthers partially covered by papillae, staminodia of fourth whorl 0.8–1 mm long, clavate, partially covered by golden, curled, appressed to erect hairs; pistil ca. 2.8 mm long, glabrous, ovary ca. 1.2 mm long, ellipsoid, style ca. 1.4 mm long, stigma ca. 2 mm long, slightly trilobed. Immature fruits 3–4 mm × 4–6 mm, ellipsoid to depressed ovoid. Immature cupules 4–9 mm × 4–8 mm, hemispheric, with a single margin, covering almost totally the fruits, tepals deciduous. Distribution and habitat.—The existing collections of Ocotea aureotomentosa are from semi deciduous forests located in the southern portion and eastern slope of the Espinhaço Range, in the western portion of the Rio Doce basin, in the State of Minas Gerais. Etymology.—The epithet ‘aureotomentosa’ refers to the dense golden and curled indument covering both vegetative and reproductive parts.

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Additional specimens examined: BRAZIL. Minas Gerais: Barão de Cocais, serra Dois Irmãos, 22 Jul 2000 [fl], W. A. Teixeira s.n. (BHCB 53506); Itambé do Mato Dentro, Distrito de Santana do Rio Preto, Cabeça de Boi, Mata do Cachoeirão, na borda, 19°25'54.7"S, 43°25'58.3"W, 25 Oct 2008 [fr], M. F. Santos & J. B. C. Marques 414 (BHCB, RB, SPF); idem, borda esquerda da mata, 19°25'54"S, 43°25'58"W, 15 Feb 2016 [fr], I. S. H. Salim et al. 7 (BHCB, HBG, MBM, NY, OUPR, SP); Mariana, 21°10'37"S 44°26'51"W, 25 Aug 2015 [fr], M. Mendes 4 (B, BHCB, P, SPF); São Gonçalo do Rio Abaixo, E.P.D.A. – Peti (CEMIG), 19°53'S, 43°22'W, 680 m alt., 5 Aug 2004 [fl], F. Raggi et al. 16 (BHCB); idem, 30 Aug 2004 [fl], F. Raggi et al. 18 (BHCB); idem, 19°53'33.2"S, 43°21'55.2"W, 3 Apr 2005 [fr], R.M. Ferreira & G.S. França 89 (BHCB).

Ocotea aureotomentosa appears to be closely allied with the species of the O. aciphylla group (Rohwer, 1986), as it shares with them branches with continuous growth, papillose anthers, and deep cupules, although the cupules are only known from the immature stage. Among the species included in the O. aciphylla group (Rohwer, 1986), O. aureotomentosa most closely resembles O. aciphylla. Both species live in the Brazilian Atlantic forest, although O. aciphylla also lives in the Amazonian forest and gallery forests of the Cerrado (Rohwer, 1986). Ocotea aureotomentosa is also similar to species of the O. indecora group, which also have papillose anthers and deep cupules, but those species are immediately separable from O. aureotomentosa in having branches with rhythmic growth (Rohwer, 1986; Assis & Mello-Silva, 2010). With the discovery of O. aureotomentosa, 19 species of Ocotea, with strictly bisexual flowers, have been found in the Brazilian Atlantic forest. These include: three species of the Ocotea aciphylla group (cf. Rohwer, 1986): O. aciphylla, O. aureotomentosa, and O. beyrichii (Nees) Mez; 13 species of the Ocotea indecora group (cf. Rohwer, 1986; Assis & Mello-Silva, 2010): O. beulahiae Baitello, O. calliscypha L. C. S. Assis & Mello-Silva, O. ciliata L. C. S. Assis & MelloSilva, O. fasciculata (Nees) Mez, O. indecora (Schott) Meisn. ex. Mez, O. lanata (Nees & Mart.) Mez, O. leucophloea (Nees & Mart.) L. C. S. Assis & Mello-Silva, O. marcescens L. C. S. Assis & Mello-Silva, O. mosenii Mez, O. odorifera (Vell.) Rohwer, O. prolifera (Nees & Mart.) Mez, O. sassafras (Meisn.) Mez, and O. virgultosa (Nees) Mart. ex. Mez; and three isolated species: O. catharinensis Mez, O. cryptocarpa Baitello, and O. porosa (Nees & Mart.) Barroso (Mez, 1889; Rohwer, 1986; Baitello, 1993, 2001; Assis & Mello-Silva, 2009, 2010).

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Acknowledgments We are grateful to the Editor-in-Chief, Benjamin Torke, and two anonymous referees for providing constructive comments on an early draft of this paper, Marília Mendes for collecting flowering materials, and Bárbara Rossi for making the beautiful illustration.

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