Myrcia pinifolia Cambessèdes, 1832

Lima, Duane F., Dos Santos, Leidiana L., Goldenberg, Renato & Lucas, Eve J., 2017, New species of Myrcia sect. Aulomyrcia and notes on Myrcia pinifolia (Myrtaceae), Phytotaxa 312 (1), pp. 94-102 : 98-100

Myrcia pinifolia Cambessèdes in Saint-Hilaire et al. (1832: 333). ( Figures 2 and 3 ).

Type:— BRAZIL. Goiás: in sabulosis partis australis provinciae Goyaz loco alto dicto Chapadão et in montibus Serra das Caldas prope aquas thermales, s.d., Saint-Hilaire 882 (lectotype P [ P00161382 ]!, designated here; isolectotypes F-photo!, MPU-photo!, P [ P00161381 ]!, P [ P00161383 ]!, P [ P00161384 ]!, P [ P00161385 ]!) .

≡ Aulomyrcia pinifolia (Cambess.) O. Berg (1855: 35) .

= Myrcia paracatuensis var. linearis Mattos (1975: 2) , syn. nov. Type:— BRAZIL. Goiás: Capelinha de Sto. Antonio , 21 August 1894, A. Glaziou 21133 (holotype MVM; isotypes BR!, C!, G!, K-2!, LE, P-2!, RB!).

Distribution and Habitat:— Myrcia pinifolia has been collected in rocky and sandy soils in cerrado vegetation from the Brazilian states of Goiás, Mato Grosso, Minas Gerais and Distrito Federal.

Phenology:— Myrcia pinifolia was collected with flowers between July and February; with fruits in October.

Etymology:—from the Latin words ‘pini’ and ‘folia’, meaning respectively ‘pine’ and ‘leaf’, alluding to the resemblance of the narrow leaves to those of Pinus Linnaeus (1753: 1000 ; Pinaceae ).

Conservation status:— Myrcia pinifolia is relatively widely distributed in central Brazil and Minas Gerais. However, it occurs in cerrado vegetation, a biome severely fragmented and disturbed by human actions. Few collections of Myrcia pinifolia were registered inside protected areas (Caldas Novas and Serra dos Pireneus State Parks). The species has an area of occupancy (AOO) of ca. 48 km 2 and can be considered Endangered (EN) following the criteria B2a, biii, biv ( IUCN 2012): this species has an AOO smaller than 500 km 2 (criterion B2) and occupies a severely fragmented region presently subject to deforestation, that is likely to further reduce its habitat (criteria a, biii, biv).

Discussion:— Myrcia pinifolia is a glabrous sub-shrub characterized by linear leaves, 9–12 times longer than wide, with obtuse to rounded apices and acute bases, plane margins and midveins slightly channelled to flat on the adaxial surface. Petioles are very short, generally pinkish and somewhat swollen, up to 1 mm long, but sessile leaves can also be found. Inflorescences are generally panicles, delicate and slightly asymmetric. Flower buds are usually depressed globose, with acute bases that widen abruptly upwards, often pinkish, with five free calyx lobes that may be internally glabrous or lightly pubescent. The ovary is bilocular with two ovules per locule.

Myrcia pinifolia joins M. myrtillifolia , M. coelosepala , M. littoralis , M. ramuliflora and their synonyms, as unexpected additions to Myrcia sect. Aulomyrcia . Recent systematic reviews ( Lucas et al. 2016; Lima et al. in prep.) reveal these latter five species, that were previously assumed related to tri-locular Myrcia guianensis ( Aublet 1775: 506) De Candolle (1828: 245) in clade 4 (sensu Lucas et al. 2011), are better placed in Myrcia sect. Aulomyrcia . The same five species share a distinctive midrib that narrows abruptly from the petiole, beginning wide and sulcate (adaxially) and ending so narrow as to be almost absent and flattened. Myrcia pinifolia is placed in the informal species group C of Myrcia sect. Aulomyrcia (sensu Lucas et al. 2016) .

Many specimens with 3-locular ovaries, globose flower buds, longer leaves and reduced inflorescences were misidentified as Myrcia pinifolia in herbaria. These specimens represent in fact Myrcia depauperata Glaziou (1908: 228) , a nomen nudum soon to be validated (P.O.Rosa pers. comm.; see also Rosa 2015) and here treated as Myrcia sp. Molecular phylogenies based on plastid and nuclear data ( Staggemeier et al. 2015, Lima et al. in prep.) show a clear separation between bi- and tri-locular species: Myrcia pinifolia emerges in the consistently bilocular Myrcia sect. Aulomyrcia (clade 9 sensu Lucas et al. 2011), while Myrcia sp. groups with other trilocular species within clade 4 (sensu Lucas et al. 2011).

Mainly due to similarities in habit and leaf shape, Myrcia pinifolia also resembles M. linearifolia Cambessèdes (1832: 148) , M. lignosa D. Villarroel & Proença (2013: 261) and M. macrocalyx Faria & Soares-Silva (2015: 181) , all of them belonging to Myrcia sect. Myrcia (clade 5 sensu Lucas et al. 2011). These species are promptly distinguished by the characters presented in Table 1.

Myrcia pinifolia was described by Cambessèdes based on Saint-Hilaire 882. Although Cambessèdes’ types are housed at MPU ( Stafleu & Cowan 1976), duplicates of M. pinifolia bearing his handwriting were found in P, indicating that he analyzed both specimens likely before the distribution of these duplicates. In this case, a lectotype must be assigned for Myrcia pinifolia and the selected material (P[00161382]) is a complete specimen that well-match the protologue.

Myrcia paracatuensis Kiearskou (1893: 99) var. linearis Mattos (1975: 2) is easily distinguished from the typical variety by its much narrower (1–2 mm wide) and sessile or subssesile leaves and match exactly the morphology of M. pinifolia ; as a result, the former is synonymized under the latter.

Material examined:— BRAZIL. Distrito Federal: Brasília, área do Cristo Redentor , 16 August 1988, R. C. Mendonça 1046 ( RB!) ; 30 August 1988, D. Alvarenga 79 ( RB!) ; R. C. Mendonça 1069 ( RB!) ; 3 October 1990, P. S. Câmera & M. Dias 48 ( K!) ; Sítio do Ipê , cerrado, 4 October 1989, V. F. Ferreira 4274 ( RB!) ; Estação Ecológica do Jardim Botânico de Brasília, área do Cristo Redentor , 2 July 2006, C. M. L. Viana, R. G. Chacon & V. F. Paiva 4 ( BHCB). Goiás: Serra dos Cristaes, 15 September 1875, Glaziou 21132 ( BR!, C!, G!, K!, LE, P!, RB!) ; Cascade do Abbade, près de l’eau, 17 July 1894, Glaziou 21131 ( BR!, C!, G!, K!, LE, P!). Mun. Caldas Novas, Parque Estadual de Caldas Novas, 13 August 2009, D. I. Junqueira 536 ( K). Mun. Cristalina, Cachoeira, 7 October 1981, G. Hatschbach 44075 ( C!, MBM!, SPF!) ; ca. 15 km de Cristalina em direção a Campo Alegre de Goiás, 8 September 1998, V. C. Souza, L. Capellari Jr., J. P. Souza & F. F. Mazine 21344 ( ESA!, SP!) ; V. C. Souza , L. Capellari Jr., J. P. Souza & F. F. Mazine 21346 ( ESA!, UB) ; cerrado, 5 November 2014, T. N. C. Vasconcelos 505 ( K!, UB) ; próximo as Lages, ca. 12 km ao sul de Cristalina, campo sujo, 30 July 2011, J. E. Q. Faria, M. R. C. Cota & P. R. F. Amorim 1494 ( BHCB, HUEG, UB). Mun. Pirenópolis, Serra dos Pirineus, 26 January 1991, N. L. Menezes 1239 ( SPF!, UPCB!). Mun. Planaltina, a 14 km da cidade de Planaltina-GO, a 5 km da Lagoa Formosa e a 600 m do Córrego Maranhão, 9 October 1992, J. Fontella & J. E. de Paula 2832 ( RB!) ; J. Fontella & J. E. de Paula 2854 ( RB!). Mun. São Gabriel, arredores, 7 November 1991, G. Hatschbach, M. Hatschbach & J. M. Silva 55873 ( C!, MBM!, MO). Mato Grosso: Próximo à Fazenda 3 Marias, June 1981, J. P. S. Lima 99 ( RB!). Mun: Itiquira, arredores, 11 February 1970, G. Hatschbach 34041 ( MBM, SP!). Minas Gerais: Mun. Corinto, Estrada Corinto-Várzea da Palma , km 47, 2 October 1965, A. G. Ferreira & M. Marques 51 ( SP!) ; M. E. R. Matos et al. 47 ( SP!) ; M. E. R. Matos, A. B. Gusman & F. Chacur 42 ( SP!). Mun. Paracatu , ramal entrando a NE da BR040 , 30 October 2010, L. P. de Queiroz, A. S. Conceição, J. G. Carvalho-Sobrinho & R. Machado 15057 ( HUEFS) .

Figures

FIGURE 2. Distribution map of Myrcia tetraloba (circles) and M. pinifolia (triangles). BA: Bahia; DF: Distrito Federal; GO: Goiás; MG: Minas Gerais; MT: Mato Grosso.

FIGURE 3. Lectotype of Myrcia pinifolia Cambess. (Saint-Hilaire 882, P [P00161382]). Image provided by the Muséum National d’Histoire Naturalle, Paris. <https://science.mnhn.fr/institution/mnhn/collection/p/item/p00161382>.