Miconia anchicayensis Gamba & Almeda, 2014

Gamba, Diana & Almeda, Frank, 2014, Systematics of the Octopleura Clade of Miconia (Melastomataceae: Miconieae) in Tropical America, Phytotaxa 179 (1), pp. 1-174 : 49-51

5. Miconia anchicayensis Gamba & Almeda , spec. nov. ( Fig. 20 )

Related to M. approximata , M. chocoensis , and M. quadridomius in its densely fasciculate glomerules. It is distinguished by its tree habit, sparsely lanate vegetative indumentum, and glabrescent abaxial foliar surfaces.

Type: COLOMBIA. Dept. Valle: Mpio. Dagua, corregimiento El Queremal, P.N.N. Farallones, Alto Anchicayá. Trail off of (upslope) Quebrada La Riqueza. Cordillera Occidental , vertiente occidental, 03°35.683’N, 76°53.521’W, 550–650 m, 6 February 2011, Almeda et al. 10266 (holotype: COL!; isotypes: CAS!, CUVC!, HUA!, NY!) .

Tree 3 m tall. Upper internodes terete to rounded-quadrate (1–) 2.5–3.7 cm long, cauline nodes terete becoming slightly compressed with age, nodal line present. Indumentum on branchlets, petioles, adaxial leaf surface at the base, primary and secondary veins abaxially, bracts, hypanthia, calyx lobes abaxially, and calyx teeth densely to moderately composed of whitish to brownish elongate slightly roughened trichomes 0.5–1.5 mm long, each trichome deflexed and somewhat flattened. Leaves of each pair somewhat anisophyllous in size; subsessile to petiolate, the terete to slightly compressed petioles 0.5–1.7 cm long, narrowly canaliculate adaxially; larger blades

SYSTEMATICS OF THE OCTOPLEURA CLADE OF MICONIA

Phytotaxa 179 (1) © 2014 Magnolia Press 49 22–28 × 8.2–12.3 cm, smaller blades (8.2–)14–18.5 × (4.1–) 6.2–9 cm, oblong-elliptic to elliptic-obovate, some smaller blades widely elliptic, the base acute to somewhat rounded, the margin entire to obscurely crenate, the apex long-acuminate; chartaceous; adaxial surface of mature leaves, primary and secondary veins glabrescent, the indumentum denser toward the base of younger leaves, the tertiary and higher order veins glabrous; abaxial surface glabrous, the tertiary and higher order veins sparsely covered with resinous short-stalked glands to 0.1 mm long with thin-walled short to elongate heads; 5- or 7-nerved, including the tenuous marginals, areolae 0.6–0.8 mm, abaxially the primary and secondary veins impressed, the tertiary and higher order veins slightly so, abaxially the primary and secondary veins elevated and terete, the tertiary and higher order veins elevated-terete to flat. Inflorescences a congested, axillary and fasciculate multiflorous glomerule to 1 cm long, sessile, unbranched, occasionally paired or appearing verticillate in the upper leaf axils but mainly on defoliated nodes; bracts minute and concealed by dense indumentum ca. 0.5 × 0.3 mm, narrowly ovate, the apex bluntly acute, early deciduous to persistent in fruit. Flowers 5-merous, sessile or on minute pedicels to 0.3 mm long. Hypanthia at anthesis 2.8–3 × 1.5–1.7 mm, free portion of hypanthium 1.3–1.5 mm long, suburceolate to globose, bluntly 10-ribbed, the elongate slightly roughened trichomes somewhat subulate, ridged on the inner surface, minutely glandular, the glands sessile and rounded, the torus adaxially densely covered with short-stalked glands 0.1–0.2 mm long with thinwalled short to elongate heads. Calyx open in bud and persistent in fruit; tube ca. 0.2–0.25 mm long, adaxially with the same vestiture as the inner surface of the hypanthium, abaxially with the same indumentum as the outer hypanthial surface; lobes 1.5 × 1 mm, rounded-ovate to triangular, the margin entire, the apex bluntly acute, adaxially moderately covered with translucent elongate slightly roughened trichomes to 0.5 mm long, densely intermixed with a hyaline understory of slightly furrowed more or less stalked glands ca. 0.08 mm long, reflexed at anthesis; exterior calyx teeth 0.7 mm long, subulate, inserted on the apical half of the calyx lobes and projecting beyond them, but frequently concealed by the dense indumentum. Petals 2.7–2.9 × 1.3 mm, oblong, the margin entire, the apex bluntly acute, white, glabrous on both surfaces, reflexed at anthesis. Stamens 10; filaments 2.2–2.7 × ca. 0.4 mm, white, glabrous; anther thecae 1.9–2 × 0.4–0.5 mm, oblong-obovate, slightly emarginate at the apex, opening by one dorsally inclined pore ca. 0.2 mm in diameter, yellow turning brown with age; connective somewhat darker than the thecae, its prolongation and appendage 0.8–0.9 mm long, the appendage lanceolate, acute at the apex, copiously gland-edged and covered with short-stalked glands 0.15–0.22 mm long with conspicuously rounded heads, denser dorsally and also present at the base of the connective. Ovary 5-locular, completely inferior 1–1.5 mm long at anthesis, the apical collar 0.9 × 0.9 mm, subcylindric to conic, densely glandular-puberulent, with the same glands as the torus adaxially; style 5.8–6.1 mm long, narrowed distally (i.e. tapering), white, glabrous, exserted at anthesis; stigma truncate to expanded truncate. Berries 4 × 5 mm when immature (on dry specimen), globose-oblate, probably orange at maturity, the hypanthial indumentum persistent on immature fruits. Seeds (on immature fruits) 0.41–0.51 × 0.3–0.32 mm, pyramidal, brown; lateral symmetrical plane triangular, the highest point near the central part of the seed, with a foot-like projection at the micropylar end; antirapahal symmetrical plane suboblong; raphal zone suboblong, ca. 90% the length of the seed; multicellular sculpture rugose throughout the seed; individual cells elongate, anticlinal boundaries slightly channeled, irregularly curved; periclinal walls convex, low-domed to nearly flat, microrelief striate.

Additional specimens studied:— Only the type gathering was available for study.

Illustration:— Fig. 19 .

Common names and documented uses:— None recorded.

Habitat, distribution and ecology:— A local and uncommon species known only from cloud forests at “Alto Anchicayá” in the department of Valle in Colombia ( Fig. 12 ) at 550–650 m. This is a wet zone that belongs to the Chocó, a rich region in fauna and flora .

Phenology:— Collected in flower and with inmature fruits in February.

Etymology:— The specific epithet refers to the only area where this species has been collected, “Alto Anchicayá”, in Valle, Colombia.

Discussion:— Miconia anchicayensis belongs to the Approximata subclade, and is distinct from its closest relatives by virtue of its arborescent habit, densely fasciculate glomerules, almost glabrous abaxial foliar surfaces and venules, and complete lack of dendritic trichomes with short to long thin-walled arms throughout the plant. The indumentum, althought sparser, and the flowers of this species are more similar to M. chocoensis ; the petal and anther morphology of both are indistinguishable. However, these species are not sister to each other. The phylogenetic analyses performed here showed that M. anchicayensis seems to be closer to M. aurantiaca and M.

50 Phytotaxa 179 (1) © 2014 Magnolia Press

GAMBA & ALMEDA

evanescens . Although more information is needed in order to better resolve the phylogenetic relationships between these three species, it is interesting to point out that the sessile fasciculate glomerules within the Approximata subclade could have evolved at least twice within this clade.

Conservation status:— Critically endangered CR D. The only locality where this plant is known from is a protected area inside the Farallones National Park in Valle, Colombia.

Figures

FIGURE 12. Distributions of Miconia anchicayensis and M. chocoensis, M. approximata, M. atropurpurea, M. aurantiaca and M. aff. aurantiaca.

FIGURE 19. Miconia anchicayensis. A. Habit, showing detail of abaxial foliar base. B. Flower. C. Stamen, lateral view (left), abaxial view (right). D. Berry, top view (top), lateral view (bottom). E. Seed, from immature fruit. Based on Almeda et al. 10266, CAS. Drawn by Sean V. Edgerton.

FIGURE 20. Miconia formicaria. A. Habit, showing detail of formicarium at adaxial foliar base. B. Flower. C. Petal, abaxial view. D. Stamen, abaxial view (left), lateral view (right). E. Berry. F. Seed. Based on Almeda et al. 10274, CAS. Drawn by Sean V. Edgerton.