Myrcia lenheirensis Kiaerskou (1893: 98)

Santos, Matheus F., Lucas, Eve & Sano, Paulo T., 2018, A taxonomic monograph of Myrcia sect. Sympodiomyrcia (Myrteae, Myrtaceae), Phytotaxa 380 (1), pp. 448-450 : 448-450

10. Myrcia lenheirensis Kiaerskou (1893: 98) ( Figures 6A , 29 and 30 )

≡ Eugeniopsis angustifolia O. Berg (1857 –1859: 143). Marlierea angustifolia (O.Berg) Mattos (1967: 333) . Type:— BRAZIL. Minas Gerais, no date (fl.), Sellow s.n. (lectotype K [barcode K000330701]! designated by Santos et al. (2016b), isolectotypes BR [barcode 825917]!, LE [barcode LE00004006]!, P [barcode P00217955]!)

Shrub to tree 1.5–10.0 m high. Epidermal peeling sometimes present in immature parts; trichomes brown to white (rarely ferruginous), 0.2–0.4 mm long. Twig when immature brownish (when dry), flattened, keeled, with scattered trichomes to glabrous; mature twig greyish (when dry), cylindrical, cortex slightly cracked, glabrous; branching monopodial (rarely sympodial), 2–3 branches per node, epidermal protrusion absent at the nodes (present only when branching is sympodial), internode 0.2–0.9 cm long; cataphyll scale-like, 1–4 × 1 mm, usually present only at the basal internode of a new branch, early deciduous, free, ovate, externally with scattered trichomes to glabrous, internally glabrous; terminal node with central bud developed and lateral ones undeveloped or only one developed, with scattered trichomes to glabrous. Leaf concolorous, chartaceous, blade 0.9–2.6 × 0.2–0.8 cm, lanceolate, narrowly elliptic, elliptic or oblanceolate, apex acuminate or rounded, base attenuate, narrowly cuneate or cuneate, margin plane or slightly revolute in the base, secondary veins ca. 1 mm apart, held at an angle of 40–70° relative to the midvein, marginal vein 0.2–0.5 mm from the margin, tertiary veins inconspicuous; adaxial surface glabrous, midvein sulcate in the first half and flat in the second half, secondary veins inconspicuous, pellucid dots conspicuous, from 5 to 15 per mm 2; abaxial surface with scattered trichomes to glabrous when immature, glabrous at maturity, midvein raised, secondary veins inconspicuous (rarely slightly raised), pellucid dots conspicuous, from 5 to 15 per mm 2; petiole 1–2 × 1 mm, canaliculate to semicylindrical, with scattered trichomes to glabrous when immature, glabrous at maturity. Inflorescence 1–2 × 1.0– 3.5 cm, corymbiform, without terminal dichasia (only the central flower), axillar at the terminal or subterminal nodes, terminal dichasia usually with three flowers, 1–6 flowers, rachis glabrous, 1–2 branching at the base, first internode of central rachis 0.5–1.0 mm wide, cylindrical to flattened, distal internodes flattened, opposite branching, 1–3 branching per node, epidermal protrusion present at the nodes. Bract 0.8 × 0.4 mm, deciduous, lanceolate, concave, apex acuminate, base truncate, adaxial and abaxial surfaces glabrous. Pedicel 2–10 mm long, cylindrical, glabrous. Bracteole 1.0–1.2 × 0.4 mm, deciduous, lanceolate, elliptic or triangular, concave, apex acute or rounded, base truncate, adaxial and abaxial surfaces glabrous. Floral bud 1.2–3.0 × 0.8–1.6 mm, turbinate. Hypanthium 0.6–1.2 mm extending above the summit of the ovary, not tearing at anthesis, externally glabrous, pellucid dots conspicuous, internally glabrous; calyx 4–merous, lobes 0.2–1.2 × 0.8–2.6 mm, distinct from the hypanthium, deciduous, depressed ovate or widely depressed ovate, concave, apex rounded, base truncate, externally with scattered trichomes to glabrous, internally puberulent; corolla 4–6–merous, petals light brown to white, 1.2–2.0 × 0.6–1.8 mm, widely depressed ovate to ovate, concave, apex rounded, base truncate, externally with scattered trichomes to glabrous, internally puberulent to glabrous; staminal ring 0.2–0.4 mm wide, glabrous, stamens 83–136, filament 0.8–3.6 mm long, glabrous, anther 0.16–0.24 × 0.24–0.40 mm, square, oblong or transversely oblong; ovary 0.4–0.8 × 0.8–1.2 mm, 2–locular, each locule with two ovules, style 4.0– 4.4 mm long, glabrous, stigma punctiform, papillose. Fruit green when immature, vinaceous at maturity, 5–9 × 5–8 mm, depressed globose or globose, base rounded, glabrous, remnants of calyx lobes present or not; seeds 1–3.

Distribution and Habitat:— Myrcia lenheirensis is distributed in campo de altitude, campo rupestre, rainforest and semideciduous forest of eastern São Paulo, southeastern Minas Gerais and southern Espírito Santo states (Atlantic Forest domain), always above 1000 m ( Figure 30 ). It is found in the forest understory, forest edge and occasionally in open areas.

Phenology:— Myrcia lenheirensis was collected with flowers from October to January and with fruits from March to November (mature fruits in June).

Conservation Status:— Despite the relatively wide Extent of Occurrence (ca. 72,000 km 2), the Area of Occupancy of Myrcia lenheirensis is only 40 km 2 and the species is restricted to altitudes above 1000 m of elevation, uncommon along its distribution. Myrcia lenheirensis is known from less than ten localities (some in protected areas) and is endemic to the Atlantic Forest, of which only 7.5% of its original area remains ( Myers et al. 2000). These data suggest Myrcia lenheirensis should be classified as Vulnerable (VU, criteria B2a, biii; IUCN 2001).

Discussion:— Myrcia lenheirensis has little morphological plasticity and is very distinct from other species of M y rcia sect. Sympodiomyrcia. It is characterized by: essentially glabrous structures; immature twigs keeled; monopodial vegetative branching; short internodes; cataphyll scars usually present only at the basal internode of a new branch; small leaves with secondary and tertiary venation inconspicuous; and pauciflorus inflorescence without lateral flowers in the terminal dichasia (just the central flower develops; Figure 6A ).

Available illustrations and images:— Mazine & Souza (2008); Santos & Sano (2012) (both as Marlierea angustifolia ).

Additional specimens examined:— BRAZIL. Unknown province /state, no date (st), Glaziou 16048 (C!, K!, LE!, NY!, RB!) . Espírito Santo: Mun. Castelo, Parque Estadual do Forno , 30 October 2004 (fl), L. Kollmann 7172 (MBM!, MBML!) . Minas Gerais: Parque Nacional do Caparaó , 18 September 1988 (fr), L. Krieger FPNC231 ( CESJ!) ; ibidem, 18 November 1988 (fr), L. Krieger s.n. (CESJ 22580!, RB!) ; Serra do Ibitipoca , 1550–1630 m, 30 September 1970 (fr), D.Sucre 7219 ( RB!) . Mun. Alto Caparaó, Parque Nacional do Caparaó , 17 August 1999 (fr), F.F.Mazine 152 (ESA!, SPF!) ; ibidem, 1700 m, 17 October 2000 (fr), W. Foster 743 (BHCB!, ESA!, MBM!, MBML!, SPF!) . Mun. Ibitipoca, Parque Estadual do Ibitipoca , 21 ° 41’11,5”S, 43 ° 53’27,5”W, 24 June 2005 (fr), I.R.Costa 578 (SPF!, UEC!) . Mun. Lima Duarte , 16 July 2005 (fr), M.F.Santos 52 ( SPF!) ; Parque Estadual da Serra do Ibitipoca , 1546 m, 21 ° 41’3”S, 43 ° 52’27”W, 11 March 2004 (fr), E.J.Lucas 263 (BHCB!, RB!) ; ibidem, 1650 m, 21 ° 41’0”S, 43 ° 52’0”W, 24 November 2004 (fl), R.C. Forzza 3692 (BHCB!, CEPEC!, K!, MBM!, RB!, SPF!) ; ibidem, 1200 m, 21 ° 40’0”S, 43 ° 53’0”W, 26 May 2005 (fr), R.C. Forzza 3986 (BHCB!, ESA!, K!, MBM!, RB!) ; ibidem, 1200 m, 21 ° 40’0”S, 43 ° 53’0”W, 26 May 2005 (fr), R.C. Forzza 3987 (CTES!, F!, K!, MBM!, RB!, SPF!) ; ibidem, 30 June 2004 (fr), E.V.S. Medeiros 348 (F!, K!, RB!, SPF!) ; ibidem, 8 October 1987 (fr), P. Andrade 1042 (BHCB!, RB!) ; ibidem, 1676 m, 21 ° 41’46”S, 43 ° 53’50”W, 31 March 2004 (fr), R.C. Forzza 3342 (K!, RB!) ; ibidem, 1670 m, 21 ° 40’44”S, 43 ° 52’59”W, 26 July 2004 (fr), R.C. Forzza 3536 (BHCB!, ESA!, RB!) ; Serra do Ibitipoca , 1350–1450 m, 14 May 1970 (fr), D.Sucre 6798 (CEPEC!, F!, MBM!, MO!, RB!, SP!, UB!) . Mun. Moeda , 1544 m, 20 ° 20’54,3”S, 43 ° 56’17,1”W, 2 February 2009 (st), F.F.Carmo 5095 ( BHCB!) . Mun. Ouro Branco, Serra do Ouro Branco , 9 January 2006 (fl), M.F.Santos 69 (BHCB!, SPF!, VIC!) ; ibidem, 9 January 2006 (fl), M.F. Santos 80 (F!, K!, RB!, SPF!, VIC!) . Mun. Ouro Preto , no date (fl), Glaziou 14840 (C!, K!, LE!) ; Estação Ecológica do Tripuí , 1300 m, 15 November 1988 (fl), M. Peron 742 (RB!, SP!) ; Parque Estadual do Itacolomi , 1600–1700 m, 26 December 1987 (fl), M. Peron 575 (CEPEC!, F!, MBM!, MO!, RB!, SP!, UB!) . Mun. Rio Preto , 10 April 2007 (fr), K.Antunes 242 (CESJ!, SPF!) . São Paulo: Serra do Mar , 1915 (fl), S.H.Paul 75 ( RB!) . Mun. Cunha, Estação Experimental Serra do Mar–Núcleo Cunha , 23 ° 14’22”S, 45 ° 0’17”W, 13 December 1996 (fl), A.R.Ferretti 58 (SP!, SPF!) . Mun. Paranapiacaba, Estação Biológica de Paranapiacaba , 30 August 1961 (fr), J.Mattos 9094 ( SPF!) . Mun. Santo André, 5 December 1961 (fl), J.Mattos s.n. (SPF 6730!) ; ibidem, 5 December 1961 (fl), J.Mattos s.n. (SP 64397!). Total: 30 specimens .

Figures

FIGURE 6. A. Myrcia lenheirensis, three terminal dichasia with only the central flower (Forzza 3692 [SPF]). B. Myrcia bicarinata, terminal dichasia with aborted lateral flowers (indicated) (Heringer 623 [IBGE]). C. Flowers of Myrcia nitida, one flower (right) with bracteole in the regular position (indicated), and the other (left) with one “migrant” bracteole at the hypanthium (indicated) (Lombardi 4532 [SPF]). D. Turbinate flower bud of Myrcia subcordata (Messias 5 [RB]). E. Clavate flower bud of Myrcia bicolor (Carvalho 6829 [SPF]). F. Obovate flower bud of Myrcia insigniflora (Assis 83 [BHCB]). G. Cross section of flower of Myrcia subcordata after anthesis, showing the hypanthium (indicated) not torn and internally glabrous, and the narrow staminal ring above (Santos 842 [SPF]). H. Flower of Myrcia insigniflora after anthesis, with the hypanthium tearing vertically, adnate petals (indicated) and persistent (but dry) stamens (Santos 682 [SPF]). Scales: A, C, D, G and H=2 mm; B and E=1mm; F=3 mm.

FIGURE 29. Images of representative specimens of Myrcia sect. Sympodiomyrcia species: Myrcia lenheirensis (Forzza 3692 [SPF]).

FIGURE 30. Distribution of Myrcia lenheirensis (circles), Myrcia mucugensis (triangles) and Myrcia rupestris (squares). Continuous lines represent South American country and Brazilian state boundaries. The grey gradient represents elevation.