Taxonomic monograph of Myrcia sect. Eugeniopsis (Myrciinae, Myrteae, Myrtaceae), an endemic clade of Eastern South America Author Santos, Matheus F. 0000-0003-0431-1095 Universidade Federal do ABC, Centro de Ciências Naturais e Humanas, Rua Arcturus 03, Jd. Antares, São Bernardo do Campo, SP 09606 - 070, Brazil. * Corresponding author: matheus. fortes @ edu. ufabc. br, matheus _ fs @ yahoo. com. br; https: // orcid. org / 0000 - 0003 - 0431 - 1095 matheus.fortes@edu.ufabc.br text Phytotaxa 2025 2025-05-30 703 1 1 100 https://doi.org/10.11646/phytotaxa.703.1.1 journal article 10.11646/phytotaxa.703.1.1 1179-3163 16727176 14. Myrcia tenuivenosa Kiaerskou (1893: 84) . Type :— Brazil , Rio de Janeiro , mun. Nova Friburgo, 8 October 1880 (fl.), Glaziou 11989 ( lectotype C! [C10015901] [image] designated by Santos et al . 2019 ; isolectotypes BR! [523902], G! [G00222002], K! [K000170008], LE! [LE00007234] pro part (same sheet as the syntype Glaziou 17675 ), P! [P00161059], R! [R000009019] [image], R! [R000009019a] [image], US ! [00478992] [image]). Remaining syntypes :— Brazil , Rio de Janeiro , mun. Petrópolis, 30 October 1868 (fl.), Glaziou 3004 (BR! [523869], C! [C10015900] [image], K! [K000170009], P! [P00161060]); Rio de Janeiro , 1887–89 (fl.), Glaziou 17675 (C! [C10015902], K! [K000344634], LE! [LE00007234] pro parte , P! [P00161061], P! [P00161062]) ( Figures 25 , 38A–B , 39 , 40 ). = Eugeniopsis acuminatissima O. Berg (1857 –1859: 144). Marlierea acuminatissima (O.Berg) D. Legrand (1962a: 30) . Type:— Brazil , Bahia , no date (fl.), Luschnath s.n. ( holotype HAL! [HAL0089792]). Description :— Shrub to tree , 5 to 15 m high. Trichome reddish, simple or dibrachiate, 0.08–0.64 mm . Twig when young flattened, tomentose or puberulent, when mature greyish (when dry), cylindrical, cortex slightly cracked; branching monopodial, internode 1.0– 5.5 cm , node slender; cataphylls present or absent, deciduous; buds tomentose, pubescent to puberulent. Leaf concolorous or slightly discolorous, chartaceous, blade 3.3–12.0 × 0.9–4.4 cm , narrowly elliptic to elliptic or ovate, apex acuminate or caudate, base narrowly cuneate to obtuse (rarely rounded) or attenuate, margin plane, secondary veins 1–5 mm apart, held at an angle of 70–85° relative to the midvein, marginal vein 0.5–1.5 mm from the margin, tertiary veins conspicuous to inconspicuous in both surfaces, areoles 0.3–1.5 mm , pellucid dots conspicuous to barely conspicuous in the abaxial surface, 2–5 per mm 2 ; adaxial surface glabrous, secondary veins plane to slightly raised; abaxial surface puberulent to glabrous, secondary veins plane to slightly raised; petiole 3–8 × 1 mm , canaliculate, tomentose or puberulent. Inflorescence 1.5–9.0 × 1.5–5.0 cm, 8–70 flowers, usually at nodes from the previous SGU, a pair arising in a short internode with abortive central bud, or often axillar at the terminal or subterminal nodes of the SGU (central bud developing a vegetative branch) and one inflorescence per axillary bud, inflorescence pherophyll usually persistent, opposite branching (rarely subopposite), three (rarely 2–5) branching per node, rachis tomentose or puberulent, first internode of central rachis 0.5–1.5 mm wide; bracts 0.6–2.0 × 0.3–1.4 mm , deciduous, narrowly elliptic or lanceolate to ovate, concave or keeled, apex acuminate to acute, base truncate, both surfaces puberulent to subglabrate; bracteoles 0.4–1.2 × 0.1–0.4 mm , deciduous, lanceolate to ovate, concave or keeled, apex acuminate, base truncate, externally puberulent to subglabrate, internally puberulent to glabrous. Flower bud 1.2–2.0 × 0.8–1.4 mm , turbinate, sometimes with a constriction near the ovary apex, corolla apparent before anthesis; hypanthium 0.4–1.2 mm extending above the summit of the ovary, not tearing at anthesis, externally puberulent to glabrous, pellucid dots covering the whole surface; calyx 4–5–merous, lobes 0.3–0.8 × 0.3–1.4 mm , not fused, deciduous parallel to the hypanthium ring, depressed ovate to widely depressed ovate or widely ovate to very widely ovate, concave, apex rounded, externally puberulent to glabrous, internally subglabrate to glabrous; corolla 4–5–merous, petals cream to white, 0.6–1.8 × 0.8–1.8 mm , widely depressed ovate, very widely ovate or very widely obovate (rarely circular), plane to concave, apex rounded, both surfaces puberulent to glabrous; staminal ring 0.2–0.4 mm wide, puberulent to glabrous, stamens 30–70, filament 1.4–5.6 mm long, anther 0.08–0.24 × 0.16–0.40 mm , gland at the apex; ovary 0.4–0.8 × 0.4–0.8 mm , obconic, style 3.2–6.6 mm long, glabrous, stigma capitate. Fruit mature red to black, ca. 0.5 × 0.5 cm , globose, base rounded, glabrous, totally covered by pellucid dots, remnants of hypanthium and calyx present; seeds 1 or 2 per fruit. Distribution and Habitat: —This species is found within the Atlantic Forest domain, ranging from Paraná to Bahia states ( Figure 25 ). It inhabits rainforest at elevations from 20 to 1,500 meters and can be found in the canopy or undercanopy, riparian zones, and forest edge. Phenology: —Flowering occurs from August to January and in May, with a peak in October and November. Fruiting occurs from August to April, with mature fruits observed throughout this period. Conservation Status: — Myrcia tenuivenosa has a broad distribution (Extent of Occurrence is 140,626 km 2 , threshold of Least Concern), is documented in numerous protected areas, and perhaps has dense populations(considering the number of records from the same locality). The small Area of Occupancy ( 216 km 2 , threshold of Endangered; sensu IUCN 2022 ) may be attributed to limited collection efforts. Despite its restriction to the threatened Atlantic Forest, Myrcia tenuivenosa is preliminarily classified as Least Concern (LC; IUCN 2022 ). Taxonomy: — Myrcia tenuivenosa is distinctive for its ramiflorous inflorescence, typically located on the SGU of previous season, and generally appearing as paired structures at a short internode with an abortive central bud. Its flower buds are turbinate and open, with visible corolla, and the stigma is capitate—a characteristic shared only with its sister species, Myrcia hatschbachii ( Santos et al . 2017 ) . Additional diagnostic features include monopodial branching, small elliptic or ovate leaves with elongated apices, thin secondary veins that branch at an angle of 70–85° from the midvein, and flower 4-5-merous.Vernacular names for this species include “grumixama” and “vassourinha” in São Paulo and Rio de Janeiro states, respectively. Illustrations and images in previous works: — Kiaerskou (1893) , Fernandes et al . (2020) , Lannoy et al . (2021) . FIGURE 38. A–B. Myrcia tenuivenosa . A. Habit. B. Trunk and external bark. C–E. Myrcia teuscheriana . C. Habitat in Montane Atlantic Forest (Santa Teresa, Espírito Santo state, Brazil). D. Trunk and external bark. E. Flowering branch. F. Flowers and a visiting pollinator. Image credits: A) Eduardo H. P. Barretto; D–F) Vanessa G. Staggemeier. FIGURE 39. Representative specimens of Myrcia sect. Eugeniopsis : Myrcia tenuivenosa ( Santos 873 [SPF]). FIGURE 40. Representative specimens of Myrcia sect. Eugeniopsis : Myrcia tenuivenosa ( Vervloet 1666 [SPF]). Additional specimens examined:— BRAZIL . Espírito Santo : Mun. Alegre , 22 February 2000 (st.), V . C . Souza 23758 ( ESA ). Mun. Castelo , 12 February 2008 (fr.), A . P . Fontana 4805 ( MBML , RB ); ibidem 14 October 2008 (fl.), C . N . Fraga 2227 ( BHCB , K , MBML , RB ); ibidem, 27 January 2004 (fr.), L . Kollmann 6380 ( MBML , RB ); ibidem, 30 October 2004 (fl.), L . Kollmann 7180 ( MBML , SPF ). Mun. Santa Maria de Jetibá , 15 October 2003 (fl.), L . Kollmann 6308 ( MBM , MBML , SPF ). Mun. Santa Teresa , 1 December 2012 (fr.), J . E . Q . Faria 3118 ( RB ); ibidem, 30 December 1998 (fl.), L . Kollmann 1457 ( MBML , SPF ); ibidem, 11 January 2006 (fr.), R . C . Britto 60 ( MBML , SPF ); ibidem, 23 November 2013 (fr.), D. F . Lima 386 ( RB , UEC ); ibidem, 6 October 1988 (fl.), H . Q . Boudet-Fernandes 2605 ( BHCB , MBML , RB , SPF ); ibidem, 12 November 1990 (fl.), H . Q . Boudet-Fernandes 3050 ( K , MBML ); ibidem, 1 February 1995 (fr.), L . D. Thomaz 1444 ( MBML ); ibidem, 1 February 1995 (fr.), L . D. Thomaz 1456 ( MBML , UEC ); ibidem, 9 August 2007 (fl.), L . Kollmann 10018 ( MBML , SPF ); ibidem, 28 September 1999 (fl.), V . Demuner 41 ( MBML , SPF ); ibidem, 27 November 2013 (fr.), D. F . Lima 394 ( UEC ); ibidem, 27 November 2013 (fr.), D. F . Lima 396 ( MBM ); ibidem, 6 December 2001 (fl.), L . Kollmann 5153 ( MBML , SPF ); ibidem, 9 January 2003 (fr.), R . R . Vervloet 1666 ( MBML , SPF ). Mun. Venda Nova do Imigrante , 20 October 2000 (fl.), G . Hatschbach 71470 ( MBM , SP , SPF , SPSF ). Mun. Viana , 11 April 2009 (fr.), R . Goldenberg 1434 ( RB ). Paraná : Mun. Bocaiúva do Sul , 22 November 1989 (fl.), J . M . Silva 694 ( BHCB , ESA , HUEFS , MBM , PACA , UB ); ibidem, 30 October 2003 (fl.), E . J . Lucas 149 ( ESA , K , MBM ). Mun. Campina Grande do Sul , 16 November 1967 (fl.), G . Hatschbach 17868 ( MBM ). Mun. Guaraqueçaba , 10 February 1995 (fr.), S . R . Ziller 658 ( MBM ); ibidem, 15 October 1969 (fl.), G . Hatschbach 22470 ( K , MBM , NY , UEC ); ibidem, 12 October 1998 (fl.), G . Gatti 291 ( CEPEC , MBML ). Mun. Guaratuba , 10 November 1962 (fl.), G . Hatschbach 9469 ( MBM , UEC ); ibidem, 11 November 1962 (fl.), G . Hatschbach 9821 ( MBM ). Mun. Morretes , 5 November 1968 (fl.), G . Hatschbach 20202 ( MBM , NY , US ). Mun. Paranaguá , 24 October 1968 (fl.), G . Hatschbach 20124 ( MBM , NY , SPF ). Mun. Piraquara , August 2005 (fl.), M . Reginato 555 ( BHCB ). Mun. Tunas do Paraná , 11 November 1997 (fl.), J . M . Silva 2193 ( HUEFS , MBM , RB , SP , SPF ). Rio de Janeiro : unknown municipality, 3 November 1964 (fl.), S . Andrade s.n. ( RB449406 ); 15 May 1918 (fl.), P . C . Porto s.n. ( RB6320 ); 19 November 1947 (fl.), J . Falcão 20 ( RB ); 7 October 1942 (fl.), C . Carcerelli 56 ( K , RB ); Parque Nacional de Itatiaia , 17 October 1977 (fl.), L . R . Landrum 2094 ( RB ). Mun. Campos dos Goytacazes , 10 October 2015 (fl.), I . G . Costa 759 ( RB ). Mun. Itatiaia , 17 October 1977 (fl.), L . R . Landrum 2085 ( RB ); ibidem, 25 September 1940 (st.), W . D. Barros 116 ( RB ); ibidem, 28 September 1953 (fl.), unknown collector s.n. ( RB505247 ); ibidem, 30 October 1964 (fl.), S . Andrade s.n. ( RB449421 ); ibidem, 28 October 2011 (fl.), A . Lobão 1726 ( RB ); ibidem, 30 October 2011 (fl.), A . Lobão 1775 ( RB ); ibidem, 18 October 1995 (fl.), J . M . A . Braga 2916 ( BHCB , HUEFS , K , NY , RB , SPF , UEC ); ibidem, 17 October 1977 (fl.), L . R . Landrum 2083 ( RB ); ibidem, 19 September 1994 (fl.), L.Sylvestre 1095 ( RB ); ibidem, 25 September 2012 (fl.), M . C . Souza 1098 ( RB ); ibidem, 3 November 1964 (fl.), S . Andrade s.n. ( RB407671 ); ibidem, 12 December 2002 (fr.), S . J . Silva-Neto 1777 ( RB ); ibidem, 15 October 1969 (fl.), S . V . Andrade s.n. ( RB449399 ); ibidem, 19 August 2017 (fl.), T . Fernandes 132 ( RB ). Mun. Magé , 16 January 2001 (fr.), A . Quinet 57/64 ( RB ). Mun. Miguel Pereira , 8 September 2017 (fl.), M . S . Wängler 2180 ( RB ). Mun. Nova Iguaçu , 30 September 2002 (fl.), G . V . Somner 1028 ( RB ); ibidem 13 November 2001 (fl.), H . C . Lima 5927 ( MBM , NY , RB ). Mun. Paraty , 23 November 1990 (fl.), C . Farney 2515 ( RB ); ibidem, 30 January 2019 (fl.), M . Nadruz 3489 ( RB ); ibidem, 20 October 1990 (fl.), V . L . G . Klein 992 ( RB , SP , UEC ). Mun. Petrópolis , 7 September 1873 (fl.), A . F . M . Glaziou 6540 ( K , LE , P ). Mun. Resende , 10 October 1977 (fl.), G . Martinelli 3201 ( RB ). Mun. Rio Claro , 4 January 2002 (fl.), F . B . Pereira 08/139 ( RB ); ibidem, 1 August 2019 (fr.), M . Nadruz 3582 ( RB ). Mun. Teresópolis , 9 January 2013 (fr.), Finotti 299 ( RB ). Santa Catarina : Mun. São Francisco do Sul , 7 November 1957 (fl.), R . Reitz 5644 ( NY , US ). São Paulo : unknown municipality, Parque Estadual Carlos Botelho , 26 January 2003 (st.), E . J . Lucas 87 ( ESA ). Mun. Biritiba-Mirim , 30 August 1983 (fl.), A . Custodio-Filho 1461 ( SP ); ibidem 30 August 1983 (fl.), A . Custodio-Filho 1439 ( SP , SPF ). Mun. São Miguel Arcanjo , 24 September 1992 (fl.), M . Kirizawa 2730 ( SP ); ibidem 13 March 2002 (st.), O . T . Aguiar 1065 ( ESA ). Mun. São Paulo , 6 November 1945 (fl.), M . Kuhlmann 2822 ( NY , SP ); ibidem 11 July 2013 (st.), H . Kondrat 155 ( SP ); ibidem 13 October 2016 (fl.), M . F . Santos 873 ( SORO ); ibidem, 29 January 1994 (st.), R . Dislich 40 ( SPF ); ibidem, 8 March 1994 (st.), R . Dislich 62 ( SPF ); ibidem, 27 September 1995 (fl.), R . Dislich 180 ( SPF ); ibidem, 12 December 1968 (fl.), A . Rodrigues 18 ( RB , SPF , SPSF ); ibidem, 9 December 1988 (fl.), E . L . Silva 45 ( SPSF ). Mun. Sete Barras , no date (st.), A . R . Duarte 543 ( ESA ); ibidem 14 June 2005 (st.), R . A . F . Lima 471 ( ESA ); ibidem 14 September 1999 (fl.), V . B . Zipparro 1788 ( SP ); ibidem 9 November 1999 (fr.), V . B . Zipparro 1812 ( BHCB , SP ); ibidem, no date (st.), V . C . Souza 30199 ( ESA ). Mun. Ubatuba , 21 January 1997 (fl., fr.), M . Sanchez 716 ( UEC ); ibidem, 21 January 1997 (fl.), M . Sanchez 717 ( SP , UEC ); ibidem, 24 January 1996 (fl.), A . Takahashi 206 ( SP ); ibidem, 25 March 1996 (fr.), A . Takahashi 256 ( SP ) .