Miconia odoratissima L. A. Cárdenas, 2014

Cárdenas, Lizeth A., Burke, Janelle M. & Michelangeli, Fabián A., 2014, Five new species of Miconia (Melastomataceae) from the Central Peruvian Andes, Phytotaxa 188 (3), pp. 121-134 : 122-124

Miconia odoratissima L. A. Cárdenas sp. nov. ( Fig. 1 )

Tree or treelet, young stems acutely quadrangular. Leaves sessile, the base auriculate. Inflorescences a terminal panicle. Flowers 5-merous, stamens isomorphic, filaments glabrous with an inflection and narrowing from the anther base, connective with four lobes, style bending away from the anthers, glabrous; stigma capitate.

Type:— PERU. Pasco: Oxapampa, Huancabamba , sector San Daniel , 10˚26’37” S, 75˚26’57” W, 2171 m, 9 September 2006 (fl, fr) , L. Cárdenas , G. Castillo & J Mateo 820 (holotype CUZ!, isotypes AMAZ, HOXA!, HUT!, MO!, MOL, NY!, USM!) .

Tree or treelet, up to 4 m. Young stems acutely quadrangular, later becoming terete, the indumentum farinose ferruginous with dendritic trichomes, later glabrescent, internodes longitudinal ridges absent, nodal line raised and slightly darker than the stem in the shape of an inverted “ V ”. Leaves isophyllous to slightly anisophyllous, then the smaller leaves up to 20% reduced with the smaller leaf alternating sides on the branch; petiole absent, blade 20–27 × 6.5–7 cm, narrowly ovate to lanceolate, coriaceous, base auriculate, apex narrowly acute, sinus 2.5–4.0 mm, margin entire to obscurely serrulate; 1 pair of secondary veins plus 1 pair of faint marginals, plinerved, the first pair of secondaries diverging 1.8–2.0(–2.7) cm above the base, symmetrical or slightly asymmetrical (even in the same branch), the marginals basally nerved, tertiary veins percurrent, evenly spaced every 3–5 mm, the quaternaries reticulate, areoles 1.5–4 mm wide, veins impressed on the adaxial surface and raised on the abaxial surface; adaxial surface with very sparse stellate trichomes <0.15 mm wide, mostly towards the base and midvein, and on the primary and secondary veins; abaxial surface yellow to orange, with the primary and secondary veins occasionally red to crimson, with dendritic trichomes up to 0.1 mm and sparse glandular trichomes, the primary and secondary veins with dendritic trichomes 0.2 mm long. Inflorescences terminal panicle, 10–17 cm long; peduncles quadrangular, green to bright yellow, the indumentum farinose ferruginous with dendritic trichomes; bracts not seen; bracteoles not seen. Flowers with the pedicel 0.7–1 mm long. Hypanthia 1.9–2.1 mm long, shortly tubular to urceolate, 2–2.4 mm wide at the torus, external indumentum with stellate sessile trichomes <0.15 mm long, internal surface with 10 faint ridges and sparsely <0.1 mm long sessile stellate trichomes. Calyx open in bud, tube ca. 0.2 mm long at anthesis, the lobes ca. 0.4 × 0.5–0.7 mm, deltoid and round at the apex, as in the hypanthium, pale white; calyx teeth subulate, ca. 0.7 × 0.3–0.35 mm, with stellate trichomes along the entire length, slightly pink. Petals 5, 1.5–1.7 × 2.1–2.2 mm, broadly obovate to orbicular, spreading, white at anthesis (drying bright brown), glabrous, the apex retuse to deeply emarginate, the base obtuse to slightly cuneate, the margin entire, slightly incurved towards the apex. Stamens diplostemonous, isomorphic or nearly so, around the style at anthesis; filaments 1.5–2 mm long, with and inflection and narrowing 0.4 mm from the anther base, glabrous, white; anthers with 2 locules, thecae 1.5–1.8 × 0.8 mm, straight, opening by one apical to slightly ventrally oriented broad pore, yellow, connective extended <0.3 mm below the thecae, with four lobes up to 0.2 mm long, dark yellow, glabrous. Ovary 4-locular, 50–60% inferior, the free portion projecting 0.4–0.6 × ca 1.3 mm, truncate conical, with sparse stellate trichomes, 10-ribbed at the apex, with a corona of 5 setae ca, 0.2 mm long; style 5–5.7 mm long, bending away from the anthers, pale white, glabrous; stigma capitate, ca. 1 mm wide. Mature fruits or seeds not seen.

Habitat and Distribution:— Miconia odoratissima is endemic to the central forests of Peru in Huancabamba, Oxapampa where it has been collected from two neighboring localities at the border of the Yanachaga Chemillén National Park in secondary forests dominated by Clusia sp. and near streams.

Phenology:— Miconia odoratissima has only been collected in September, and was in flower at the time.

Etymology:—This new species is named for the sweet smell of its flowers, which attracted several bees at the time of collection.

Conservation Status:— Miconia odoratissima is only known from two specimens from the same locality at the edge of the Yanachaga Chemillen National Park, in an area that is highly degraded and under logging pressure. Based on the paucity of collections it should be considered Data Deficient (DD), following the IUCN criteria (2001) as implemented by the IUCN guidelines (2011). However, based on its limited distribution and endangered habitat, we recommend that this species is considered Critically Endangered.

Additional specimens examined (paratypes):— PERU. Pasco: Oxapampa, Huancabamba, La Colmena , Trocha Erica , Parque Nacional Yanachaga Chemillén , 10°26’37”S, 75°26’15”W, 2300 m, 22 Aug 2008 (fl), L Valenzuela, J . L . Mateo, & R . Rivera 11637 ( HOXA, HUT, MO!, MOL!, USM!) .

Discussion:—Vegetatively M. odoratissima resembles Miconia impetiolaris ( Swartz 1788: 70) D. Don ex de Candolle (1828: 183) var. pandurifolia Naudin (1850: 137) given their sessile and pandurate, coriaceous leaves with auriculate bases and a glabrous adaxial surface. However, M. impetiolaris var. pandurifolia (and all other described varieties) has an undulate leaf margin and abaxial leaf surface with dense stellate indument. Additionally, the inflorescence of M. impetiolaris is usually larger (over 20 cm long) and the flowers are not as densely arranged. Based on flower morphology, particularly that of the anthers, it is unlikely that these two species are closely related: Miconia odoratissima has large flowers with short yellow anthers that open by a minute pore which would place it in Miconia section Amblyarrhena ( Naudin 1850: 204) Triana ex Hook. f. in Bentham & Hook (1867: 763), while M. impetiolaris has subulate and relatively thinner white anthers with a ventrally bilobed connective, and it belongs in Miconia section Miconia ( Goldenberg et al. 2008) . Other Andean species of Miconi a with sessile leaves (but unrelated flower morphology) are Miconia asclepiadea Triana (1871: 121) , M. ferreyrae Wurdack (1960: 235) , and M. retusa Pilger (1905: 174) . Miconia asclepiadea and M. retusa have glabrous, ovate and cordate leaves that are either basally or only slightly plinerved. Miconia ferreyrae has lanceolate and basally nerved leaves with cordate to hastate bases.

Miconia odoratissima shares with M. monzoniensis Cogniaux (1908: 140) , M. barbeyana Cogniaux (1891: 872) , M. pedicellata Cogniaux (1891: 875) , M. pulgari Macbride (1929: 182) and M. terera Naudin (1850: 196) , also from Miconia section Amblyarrhena , the glabrous filaments, thecae and styles, but all of the latter species all have petiolate leaves.

The anthers of M. odoratissima have the connective with four lobes around the base of the thecae ( Fig.1 ), a character also present in M. pedicellata . However, this last species has smaller and narrower petiolate leaves, 4-locular anthers and thinner calyx teeth.

Figures

FIGURE 1. Miconia odoratissima. A. Fruiting branch. B. Detail of leaf bases. C. Flowers at anthesis in dichasium. D. Longitudinal section of a flower. E. Petal, adaxial surface. F. Antesepalous (L) and antepetalous (R) stamens on side view. G. Antepetalous stamen, dorsal view (Cárdenas 820, A–B: NY; C–G: CUZ).