Myrcia DC. ex Guill.

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: 36-42

publication ID

http://doi.org/ 10.11646/phytotaxa.50.1.3

persistent identifier

http://treatment.plazi.org/id/03C987E0-FFE5-9D2C-FF0B-FF2FF52BF8DC

treatment provided by

Felipe

scientific name

Myrcia DC. ex Guill.
status

 

3. Myrcia DC. ex Guill.  

Myrcia   is an American genus with 370 recognized species ( Govaerts et al. 2011), of which 214 are native from Brazil ( Sobral et al. 2010). It is characterized by the mostly pentamerous flowers which bears distinct calyx lobes, the ovaries with two or three biovulate locules and the embryos with two foliaceous cotyledons surrounded by a well developed hypocotyl. It is one of the four genera considered by Lucas et al. (2007) as the "core" of the subtribe Myrciinae   , and its generic limits may in a near future be subject to a reconsideration (see discussion under Calyptranthes   ).

3.1. Myrcia clavata Sobral   , sp. nov. Type: Brazil. Alagoas, mun. União dos Palmares, Serra das Bananeiras, 9 o 12.775' S, 35 o 52.480' W, 500–560 m, intact coastal rain forest (mata de encosta), 3 Nov. 2002, W. W. Thomas, M. R. Barbosa, R. L. Lemos, P. Fiaschi, S. Sant'Ana & J. L. Paixão 13224 (holotype CEPEC, isotype NY). Figure 9 View FIGURE 9 GoogleMaps   .

This species is close to Myrcia riodocensis   , from which it is kept apart through its wider leaves and pentamerous flowers.

Tree 10– 12 m. Twigs glabrous, grey, complanate, the internodes 20–50 × 2–3 mm. Leaves with petioles 1.8–3.5 × 2–2.5 mm, sometimes visible only abaxially, glabrous, canaliculate; blades elliptic, elliptic–obovate or sometimes lanceolate, 90–140 × 54–80 mm, 1.5–2.2 times longer than wide, glabrous, moderately discoloured when dry; glandular dots smaller than 0.1 mm in diameter, six to eight per square milimeter, visible and darker than the surface abaxially; apex widely acute to rounded, sometimes emarginate; base rounded to auriculate, sometimes concealing the petiole when viewed from above; midvein sulcate adaxially, strongly prominent and sometimes longitudinally wrinkled abaxially; secondary veins 18 to 20 at each side, leaving the midvein at angles about 70 degrees, visible and prominent on both sides, especially abaxially; intersecondary veins visible and somewhat prominent on both sides; marginal veins two, the inner one 2–4 mm, the outer one to 1 mm from the margin, the margin itself sometimes revolute. Inflorescences paniculiform, with triangular profile, glabrous, two to four at the apex of the branches, the main axis 80–140 × 2–2.5 mm, the axes of the first branching to 50 × 2 mm, of the second ones to 10 × 1 mm and from the third ones to 5 × 0.5 mm, complanate and not symmetrically branching along the main axis; bracts at the base of the inflorescences elliptic to lanceolate, 9–11 × 4–6 mm, at least adaxially covered with simple grey trichomes to 0.5 mm; bracts at the base of distal branches linear, to 1.5 × 0.1–0.2 mm, deciduous after anthesis; flowers mostly in triads at the apex of the distal branches, the central flower sessile and the lateral ones with pedicels to 1 × 0.2–0.3 mm (pedicels here not interpreted as a fourth–degree branching of the inflorescences), moderately covered with grey dibrachiate hairs to 0.2 mm; bracteoles linear, to 1 × 0.1 mm, deciduos before anthesis; flower buds obovate to clavate, 4–4.5 × 3 mm, glabrous, the petals mostly concealed by the calyx lobes, these five, hemispherical, more or less equal between them, 1 × 1.8–2 mm, markedly convex and incrassate, 0.2–0.3 mm thick, with brown glistening trichomes smaller than 0.1 mm adaxially; petals five, rounded, 3–3.5 × 3 mm, glabrous; stamens about 80, to 3.5 mm, the anthers globose, 0.5–0.6 × 0.6 mm, some eglandular and some bearing a small apical gland; calyx tube glabrous, 1.5 mm deep; style 6 mm, the stigma punctiform and barely papillose; ovary with three locules and two centrally attached ovules per locule. Fruits dark red when ripe, elliptic, to 10 × 8 mm, with one reniform seed to 8 × 7 mm, with brown, easily detachable testa; embryo young and attacked by insects in the examined fruits.

Distribution, habitat, phenology — this species is presently known from coastal rainforests of the municipalities of União dos Palmares and Murici, in the northeastern Brazilian state of Alagoas. Flowers were collected in November and mature fruits in March.

Conservation status — there have been distinct collection efforts in the municipalities of União dos Palmares and Murici (420 and 426 km 2 in area respectively; IBGE 2012); for the first specieslink lists 460 collections and for the second about 3200 collections ( CRIA 2012), with averages of 1 and 7.5 gatherings /km 2, respectively. Considering this, the fact that Myrcia clavata   , to our knowledge, was collected only twice, may be indicative of its rarity. Unitl new information is available, it must be scored as DD (Data Deficient; IUCN 2001).

Affinities — Myrcia clavata   is apparently related to M. riodocensis G.M.Barroso & Peixoto   (for description see Barroso & Peixoto 1990: 13), from which it is distinguished by the following characters:

1. 50 mm, 2.7–3 times longer than wide, with up to fifteen secondary veins; calyx lobes four, unequal, apiculate; Espírito Santo state .......................................................................................................................... Myrcia riodocensis   — 80 mm, 1.5–2.2. times longer than wide, with up to twenty secondary veins; caly lobes five, equal between them; Alagoas state ........................................................................................................................................... Myrcia clavata  

Etymology — the epithet is derived for the Latin word for club–shaped, alluding to the morphology of the flower buds.

Paratype: Brazil. Alagoas, mun. Murici, Bananeiras , 9 o 14'05"S, 35 o 52'61" W, 513, mata higrófila, 16 Mar. 2000, A. M   . Carvalho , W   . Thomas, Barbosa, Rodal , R   . Lemos, Sant'Ana , etc. 7146 ( CEPEC, PEUFR)   .

3.2. Myrcia lascada Sobral   , sp. nov. Type: Brazil. Bahia, mun. Barro Preto, Serra da Pedra Lascada , 13,7 km de Barro Preto, na estrada que passa pela Fazenda São Miguel em direção à serra, 14 o 46'13'' S, 39 o 12'10'' W, 600–900 m, floresta ombrófila densa submontana, 21 May 2006, M. M. M. Lopes, J. L. Paixão, L. Gomes & B. Santos 658 (holotype CEPEC; isotype BHCB). Figure 10 View FIGURE 10 GoogleMaps   .

This species is close to Myrcia palustris   , differing through its larger leaves and few-flowered inflorescences.

Tree 4– 15 m. Twigs pilose when young, with simple brown trichomes 0.8–1 mm and presenting an apical gem densely covered with such trichomes, the internodes 8–30 × 1–2 mm. Leaves with petioles 2.5–4 × 0.8–1.2 mm, with simple brown trichomes to 0.8 mm, cylindrical or adaxially applanate; blades elliptic, 38–80 × 21–35 mm, markedly discoloured when dry, lighter abaxially; glandular dots visible on both sides, up to ten per square milimeter, unequal in size, the larger ones about 0.05 mm in diameter; apex acute, widely acute or acuminate to 5 m; base cuneate; midvein sulcate and with scattered simples trichomes 0.2–0.3 mm adaxially, prominent and with scattered simple grey trichomes to 1 mm abaxially; secondary veins 12 to 16 at each side, prominent but scarcely evident adaxially, more markedly so and with scattered simple trichomes to 0.5 mm abaxially; marginal veins one or two, the inner one 1–2 mm from the margin and the outer one, when present, up to 0.5 mm from it, the margin itself thickened in about 0.2 mm. Inflorescences axillary, triflorous or racemiform, then with up to five flowers, the axis with sparse, simple and upwards curled trichomes to 0.3 mm; bracts lanceolate, 2–2.5 × 0.5 mm; the axis 15–25 × 0.5–0.8 mm, the lateral branches (or pedicels, if one should interpret the inflorescences as racemiform) 1–3 × 0.5–0.8 mm; bracteoles triangular to lanceolate, 1–2 × 1–1.2 mm, deciduous before anthesis, abaxially with trichomes 0.2–0.3 mm, with up to seven linear colleters to 0.7 × 0.05 mm at the axiles just below the flowers; flower buds globose or oblate, to 4 × 4 mm, pilose, the trichomes simple, grey, 0.4–0.5 mm, more densely over the ovary than the calyx lobes, the globe of petals visible over the calyx lobes, these widely ovate to hemispherical, very slightly unequal between them, 2.5 × 1–1.2 mm; petals globose, 5 × 4–5 mm, concave, abaxially with sparse grey trichomes to 0.2 mm; stamens about sixty, to 4 mm, the anthers oblong, 0.6 × 0.2 mm, opening slightly sinuously and with one connectival gland; staminal ring to 3 mm in diameter, with trichomes to 0.3 mm; calyx tube 0.2–0.8 mm deep; style to 4 mm, proximally with trichomes to 0.7 mm, the stigma punctiform and papillose; ovary with two locules and two centrally attached ovules per locule. Fruits immature, globose, 10–12 × 9–12 mm; seed one per fruit in the fruit examined, up to 10 × 7 mm, with light–brown papyraceous testa and immature embryo with evident radicle and two separate, foliaceous cotyledons.

Distribution, habitat and phenology — Myrcia lascada   is known from submontane rainforests at up to 900 m elev., from montane regions of the southern Bahian municipalities of Almadina and Barro Preto; flowers in March and May; fruits in August.

Conservation — the municipalities of Almadina and Barro Preto (251 and 128 km 2 in area, respectively; IBGE 2012) have been intensively surveyed recently, mostly from CEPEC staff ( Amorim et al. 2009), presenting high collection indices (2800 and 1400 collections and 11 and 10 collections / km 2, respectively); Myrcia lascada   is apparently restricted to mountain summits and may be rare. Until new information is available, its conservation status must be scored as DD (Data Deficient; IUCN 2001).

Affinities — Myrcia lascada   is apparently related to M. palustris DC.   (for description see Legrand &

Klein 1967, under Gomidesia palustris   , or Sobral 2003); the following key allows its distinction:

1. Leaves with blades to 50 × 20 mm, with up to ten secondary veins; apex obtuse, rarely acute; inflorescences with up to thirty flowers .............................................................................................................................................................. Myrcia palustris  

—. Leaves with blades to 80 × 35 mm, with up to sixteen secondary veins; apex acute or acuminate; inflorescences with three to five flowers ............................................................................................................................... Myrcia lascada  

Etymology — the epithet is allusive for the collection site of the type, Serra da Pedra Lascada.

Paratypes — Brazil. Bahia, mun. Almadina, Serra do Corcovado, 13,8 km SW de Coaraci, na estrada para Almadina , Fazenda São José , proprietário senhor Francisco , 14 o 42'21'' S, 39 o 36'12'' W, 650–900 m, 12 Aug. 2007, D. Cardoso, M GoogleMaps   . Lopes, L   . gomes, R. Perdiz, M   . Garcia & A   . Rodrigues 2129 ( CEPEC). Mun. Barro Preto, Serra da Pedra Lascada , 13,7 km de Barro Preto , na estrada que passa pela Fazenda São Miguel em direção à serra, 14 o 46'13'' S, 39 o 12'10'' W, 600–900 m, floresta ombrófila densa submontana, 13 March 2007, M GoogleMaps   . M GoogleMaps   .M. Lopes, R   . P   . Oliveira, R   . Borges & L   . Gomes 1160 ( CEPEC)   .

3.3. Myrcia teimosa Sobral   , sp. nov. Type: Brazil. Bahia, mun. Jussari, RPPN Serra do Teimoso , 15 o 09'43"S, 39 o 32'20"W, 18 Jun. 2003, A. M. Amorim, P. Fiaschi, J. L. Paixão & S. C. Sant'Ana 3701 (holotype CEPEC, isotype BHCB). Figure 11 View FIGURE 11 GoogleMaps   .

This species is close to Myrcia eximia   , differing through its leaves with up to 25 secondary veins and double marginal veins, few-flowered inflorescences and tetralocular ovaries.

Tree 2– 5 m. Twigs glabrous or with simple brown trichomes to 0.6 mm, light brown, complanate, the internodes 20–30 × 2 mm. Leaves with petioles 5–9 × 1.5–2 mm, mostly glabrous, occasionally with brown trichomes to 0.6 mm, canaliculate; blades lanceolate to ovate–lanceolate, 115–160 × 34–63 mm, 2.3–3.4 times longer than wide, mostly glabrous except for scattered simple white trichomes 0.2–0.3 mm along the midvein at the abaxial side, concoloured or moderately discoloured when dry, lighter abaxially; glandular dots about 0.1 mm in diameter, one to four per square milimeter, occasionally visible abaxially; apex acute to acuminate in 5–9 mm; base widely cuneate or rounded; midvein sulcate adaxially and strongly prominent abaxially; secondary veins 22 to 25 at each side, leaving the midvein at angles 60–70 degrees, visible on both sides, moderately prominent adaxially and markedly prominent abaxially, the surface occasionally somewhat bullate; intersecondary veins visible on both sides; marginal veins two, the inner one 2–3.8 mm, the outer one 0.3–1.2 mm from the margin, the margin itself revolute and with a yellow or brown thickening to 0.1 mm wide. Inflorescences paniculiform, with a main axis 3–20 × 1.2–1.8 mm, aborted at the first ramification, originating two second order branches 5–20 × 1.5–2 mm, these occasionally with one or two third order branchings 2–5 × 0.8–1 mm, with about six to nine flowers in triads at the apex of branches; axes with simple brown trichomes 0.2–0.3 mm; bracts narrowly triangular, 2.5–4 × 0.7–1 mm, with trichomes to 0.1 mm abaxially; pedicels absent or to 1 × 1.5 mm; bracteoles narrowly triangular, 0.8–2 × 0.5–0.8 mm, abaxially pilose as the bracts, deciduous after anthesis; flower buds obovate, 5–6 × 4 mm, the calyx lobes concealing partially the globe of the petals, the ovary densely covered with brown or grey trichomes to 0.2 mm, visibly distinct from the more scattered pilose calyx lobes, these five, triangular to widely triangular, acute, slightly unequal between them, 2.5–3.5 × 3–3.8 mm, with scattered trichomes abaxially and glabrous adaxially; petals five, rounded, 4.5 × 5 mm, adaxially glabrous and abaxially with scattered simple white trichomes to 0.2 mm; stamens about 150, to 4 mm, the anthers elliptic, 0.5 × 0.3 mm, eglandular, opening longitudinally; calyx tube glabrous, 0.5–1 mm deep; style 6–7 mm, the stigma punctiform and scarcely papillose; ovary with four locules and two centrally attached ovules per locule. Fruits unknown.

Distribution, habitat and phenology — all the collections of this species are from the private reserve Serra do Teimoso, a montane area with altitudes up to 850 m elev. in the southern Bahian municipality of Jussari ( Amorim et al. 2005). Flowers were collected in March and May; fruits in August.

Conservation — the municipality of Jussari was intensely surveyed by CEPEC staff ( Amorim et al. 2009): about 4800 collections ( CRIA 2012) were gathered along an area of 356 km 2 ( IBGE 2012), with an index of 13.5 collections / km 2. All collections of Myrcia teimosa   are from the same locality, what may be indicative of its rarity. Until new data are available, however, this species must be scored as DD (Data Deficient), according to IUCN criteria (IUCN 2001).

Affinities — Myrcia teimosa   is related to M. eximia DC.   (for description see Berg 1857 –1859: 198), a species from Minas Gerais and Bahia, from which it differs through the following characters:

1. Blades with up to fifteen secondary veins; marginal vein one, up to 2 mm from the margin; inflorescences with main axis to 80 mm, with more than twenty flowers; ovaries with two or three locules ................................. Myrcia eximia  

—. Blades with up to twenty–five secondary veins; marginal vein two, the inner one to 3.8 mm from the margin; inflorescences with main axis to 20 mm, with up to nine flowers; ovaries with four locules. ...................... Myrcia teimosa  

Etymology — the epithet is derived from the name of the collection site of the species, Serra do Teimoso. Paratypes — Brazil. Bahia, mun. Jussari, RPPN Serra do Teimoso, 15 o 09'29"S, 39 o 31'43"W, 21 Aug.

2003, P. Fiaschi, S.C. Sant'Ana & J.L. Paixão 1588 (BHCB, CEPEC); idem, 15 o 09'43"S, 39 o 32'20"W, 17 Jul GoogleMaps   .

2003, A.M. Amorim, P. Fiaschi, J.L. Paixão, Alexandre & S.C. Sant'Ana 3793 (BHCB, CEPEC).

3.4. Myrcia truncata Sobral   , sp. nov. Type: Brazil. Bahia, mun. Amargosa, serra do Timbó , mata do centro Sapucaia , 13 o 10'00'' S, 39 o 09'00'' W, 12 May 2007, J. L. Paixão, M. S. Nascimento & sr. Manoel Cheira–Cheira 1256 (holotype CEPEC, isotype BHCB). Figure 12 View FIGURE 12 GoogleMaps   .

This species is distinguished from all other Brazilian Myrcia   through its markedly basally truncate leaves.

Tree to 3 m. Twigs glabrous, brown, with internodes to 100 × 10 mm. Leaves sessile or with petioles to 1 × 4 mm, visible only abaxially; blades ovate–oblong, to 300 × 100–110 mm, discoloured, lighter abaxially; glandular dots smaller than 0.1 mm in diameter, five to ten per square milimeter; apex widely acute; base truncate; midvein sulcate adaxially and salient abaxially; secondary veins 30 to 36 at each side, moderately prominent and weakly evident on both sides; submarginal veins two, the inner one 4–5 mm, the outer one 0.8–1 mm from the somewhat revolute margin, the margin itself with a brown thickening up to 0.2 mm wide. Inflorescences axillary or terminal, paniculiform, up to twice ramified, the main axis 100–110 × 4 mm, the first order ramification to 40 × 2 mm; flowers not examined. Fruits globose, 10–12 mm in diameter, crowned by the calyx tube, this 1–1.5 mm deep, and occasionally by the calyx lobes, these five, rounded, 1–1.5 x 1 mm; seed one, to 10 × 8 mm, the testa light brown, papyraceous, easily detachable; embryo with two foliaceous cotyledons and a hypocotyl surrounding them.

Distribution — this species is presently known only from the type collection, gathered in the municipality of Amargosa, along the Atlantic rainforest domain in eastern Bahia.

Conservation — although the municipality of Amargosa (463 km 2 in area; IBGE 2012) presents a relatively high collection index (about 1260 collections, with 2.7 collections / km 2), most collections are recent (2007 onwards) and are result of apparently few collection trips. So, it seems presently adequate to score Myrcia truncata   conservation status as DD (Data Deficient)according to IUCN criteria (IUCN 2001).

Affinities — this species is readily distinguishable from all other Brazilian species of the genus through its leaves with markedly truncate bases.

W

Naturhistorisches Museum Wien

M

Botanische Staatssammlung München

R

Departamento de Geologia, Universidad de Chile

L

Nationaal Herbarium Nederland, Leiden University branch

P

Museum National d' Histoire Naturelle, Paris (MNHN) - Vascular Plants

S

Department of Botany, Swedish Museum of Natural History

J

University of the Witwatersrand

CEPEC

CEPEC, CEPLAC

NY

William and Lynda Steere Herbarium of the New York Botanical Garden

A

Harvard University - Arnold Arboretum

PEUFR

Universidade Federal Rural de Pernambuco

B

Botanischer Garten und Botanisches Museum Berlin-Dahlem, Zentraleinrichtung der Freien Universitaet

BHCB

Universidade Federal de Minas Gerais

C

University of Copenhagen

Kingdom

Plantae

Phylum

Magnoliopsida

Class

Magnoliopsida

Order

Myrtales

Family

Myrtaceae

Loc

Myrcia DC. ex Guill.

Sobral, Marcos, Grippa, Carlos R., Souza, Marcelo C., Aguiar, Osny T., Bertoncello, Ricardo & Guimarães, Thais B. 2012
2012
Loc

Myrcia clavata

Sobral 2012
2012