Microlicia colombiana HumbertoMend. & R.Romero, 2019

Mendoza-Cifuentes, Humberto, Ariza, William, Granados, David E. & Rosana Romero,, 2019, A new species of Microlicia (Melastomataceae): first record of the genus for Colombia, PhytoKeys 122, pp. 87-96 : 88-92

Microlicia colombiana HumbertoMend. & R.Romero sp. nov. Figs 1 , 2 , 3

Diagnosis.

Related to Microlicia benthamiana Triana but differs in having larger internodes, strigose nodes, linear to obovate leaf blades, trichomes between sepals, petals and pedoconective of antesepalous stamens shorter. Also related to Microlicia guanayana Wurdack but differs in having non-strigose adaxial foliar surfaces, 3-nerved leaf blades, hypanthia 10-ribbed, petals <8.5 mm long and with a rounded setose apex, and stamens with smaller dimensions.

TYPE: COLOMBIA. Boyacá: Municipio de Pisba, vereda Miraflores, Sabana de Nubacá, 2389 m elev., 5°44'7.10"N, 72°37'32.02"W, 19 Nov 2018 (fl, fr), H. Mendoza & D. Granados 22014 (holotype: FMB!; isotypes: COL!, CUVC!, HUA!, FMB!, CUVC!, UDBC!).

Description.

Denselly branched shrub 70-190 cm tall; internodes 2.4-8.1 mm long, 0.3-1.1 mm wide; young branches quadrangular becoming terete in old-basal parts, glabrous or puberulous with long-stalked glands 0.3-0.6 mm long, the stalk is curled, glands early caducous; nodes strigose, trichomes similar to the ones in the internodes; distal internodes with sessile glands. Leaves decussate, isophyllous, ascending, adaxial surface green (fresh material), abaxial surface clear pale green (fresh material), subsessile; petiole 0.3-0.7 mm long and 0.2-0.5 mm wide; blade linear to oblong, 4.1-9.9 × 1.1-2 mm, apex rounded, mucronate, frequently with a terminal seta 0.2-0.4 mm long, margin entire, revolute, frequently with sparse trichomes ca. 0.3 mm long, adaxial surface with spherical, golden glands, 0.03-0.06 mm diameter, abaxial surface glabrous or impressed with spherical golden glands 0.03-0.04 mm diameter, central vein with pale trichomes 0.2-0.3 mm long; 3-nerved or slightly plienerved to 0.4 mm from the base (visible only on adaxial surface), middle vein impressed on adaxial surface. Flowers 5-merous, axillary, among the distal leaves, solitary, diplostemonous; pedicel 1.2-2 mm long. Hypanthium 3-3.7 × 2.2-2.5 mm, obconical or terete, externally 10-ribbed, with short-stalked glands, glands 0.03-0.04 mm diameter; internally glabrous. Calyx lobed; undivided part of 0.2-0.3 mm long; lobes 2.1-2.7 × 0.9-1.4 mm (excluding seta), narrowly triangular, apex acute with a terminal seta 0.3-0.9 mm long, adaxial surface glabrous, abaxial surface towards the base with short-stalked glands similar to the hypanthium; pale trichomes 0.6-1 mm long intercalated with lobes. Petals 6.8-8.5 × 4.3-5 mm, obovate, pink, darker in the venation, glabrous, apex rounded. Stamens 10, strongly dimorphic, glabrous, anthers polysporangiate; small (antepetalous) stamens 5, filaments 2.6-5.3 × 0.2-0.4 mm, glabrous, light purple; pedoconnective 0.7-1.5 mm long, arcuate, yellow; ventral appendage 0.3-0.7 × 0.3-0.4 mm, globose or lobed, yellow; thecae 1.8-2 × 0.5-0.8 mm (including the rostrum), oblong, yellow, rostrum 0.3-0.4 mm long, with a ventrally oriented pore 0.1-0.3 mm diameter; large (antesepalous) stamens 5, filaments 3.2-4.9 × 0.2-0,4 mm, glabrous, light purple; pedoconnective 1.9-2.9 mm, ventrally arcuate, light purple; ventral appendage 1.1-2.2 × 0.9-1.1 mm, spatulate, light purple towards the base and yellow towards the apex; thecae 2.2-2.4 × 0.6-0.7 mm (including the rostrum), oblong, red, rostrum 0.3-0,5 mm long, with a ventrally oriented pore 0.1-0.2 mm diameter. Ovary 1.6-2.5 × 0.8-1.4 mm, oblate, superior, 3-locular, glabrous, apex rounded; style 3.3-5.2 mm long; stigma punctiform, 0.1-0.2 mm diameter. Capsule 3.2-3.4 × 2.1-2.3 mm, oblong, dehiscing into 3 valves from the apex, enveloping hypanthium early caducous. Seeds ca. 0.6 × 0.2-0.3 mm, ovoid to oblate, beige; testa lightly reticulate.

Phenology.

Collected with flowers and fruits in July and November. In the area, there is only one rainy period with the highest levels of precipitation between the months of May to July and with less precipitation between December to February ( Jaramillo and Chaves 2000). Flowering coincides with less rainy periods.

Habitat and distribution.

Microlicia colombiana is endemic to northeastern Andes of Colombia towards the Orinoquian flank. This species is only known from the type locality in the department of Boyacá near the southern border of Pisba National Natural Park, and a nearby second locality in the department of Casanare, between 2000 to 2400 m elevation (Figure 4A ). It grows in open areas of sub-páramo vegetation on white sandy soil covered with sphagnum (Figure 3 ).

Etymology.

The specific epithet refers to the restricted occurrence of the new species to Colombia and for being the first record of the genus in this country.

Specimens examined

(Paratypes). COLOMBIA. Boyacá: Municipio de Pisba, vereda Miraflores, Sabana de Nubacá, 2389 m elev., 5°44'7.10"N, 72°37'32.02"W, 1 nov 2017, fl, fr, D. Granados 811 (CUVC, FMB); vereda Miraflores, Sabana de Nubacá, 2389 m elev., 5°44'7.10"N, 72°37'32.02"W, 19 nov 2018, fl, fr, H. Mendoza & D. Granados 22015 (FMB, HUA, UPTC), 22016 (COL, FMB, HUA, UPTC, UIS). Casanare. Municipio de Yopal, corregimiento El Morro, vereda Perico, finca La Reserva, 1300-2000 m elev., 17 July 1993, fl, fr, F. Castro 18718 (FMB, UDBC).

Figures

Figure 1. Microlicia colombiana HumbertoMendR. Romero. A Node at basal portion of a branch B Node with spherical golden glands at the distal part of a branch C Leaves, adaxial (left) and abaxial (right) surfaces D Leaf adaxial surface, with detail of indumentum E Leaf abaxial surface, with detail of indumentum (A-E from H. Mendoza & D. Granados 22014 (FMB). All photos by Humberto Mendoza-Cifuentes).

Figure 2. Microlicia colombiana HumbertoMend. & R. Romero. A Floral bud B Lateral view of the calyx and hypanthium in open flower C Petal D Antepetalous stamen E Top view of ventral appendage of the connective F Lateral view of ventral appendage of the connective G Polysporangiate anther H Antesepalous stamen I Top view of ventral appendage of the connective J Anther K Gynoecium L Longitudinal section of the ovary M Horizontal section of the ovary N Capsule covered by hypanthium O Open capsule P Seeds (A-P from H. Mendoza & D. Granados 22014 (FMB). All photos by Humberto Mendoza-Cifuentes).

Figure 3. Microlicia colombiana HumbertoMend. & R. Romero. A Habit B Flowering branch C Sub-paramo habitat at te type locality D, E Sandy soils and substrate of the type lovality (all photos by David Granados).

Figure 4. Distribution of Microlicia. A Distribution of M. colombiana and the most similar species in northern South America (Red dots: M. colombiana; Yellow point: M. guanayana; Green triangles: M. benthamiana) B Distribution of Microlicia in South America and wind currents (Red point depicts distribution of M. colombiana, white dots are other species of the genus).