Miconia palenquensis ( Wurdack 1978: 302 ) 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 : 107-108

23. Miconia palenquensis ( Wurdack 1978: 302) Gamba & Almeda , comb. nov. Basionym: Ossaea palenquensis Wurdack. Type: ECUADOR. Prov. Los Ríos: km 56 Quevedo-Santo Domingo , Río Palenque Biological Station , Trail 1, 150– 220 m, 7 October 1976, Dodson & Gentry 6553 (holotype: US!; isotypes: MO!, QCA-2 sheetsinternet images!, UC-internet image!).

Shrub to 2.5–3 m tall. Upper internodes (3.4–7.4 cm long) and cauline nodes terete, nodal line absent. Indumentum on branchlets, petioles when present, adaxial surface of young leaves, primary, secondary, tertiary and higher order veins abaxially, inflorescence axes, bracts, bracteoles, pedicels, hypanthia, and exterior calyx teeth copiously to moderately composed of brownish dendritic trichomes 0.1 mm long with short axes and few-moderate number of terete arms. Leaves of each pair isophyllous; sessile or with an inconspicuous terete petiole 0.2–0.3 cm long; blades 16–23 × 8–11 cm, oblong-elliptic to slightly obovate-elliptic, the base rounded-cordate and amplexicaul, the margin distantly undulate-serrulate, the apex bluntly acute, firm-chartaceous; mature leaf surface adaxially glabrescent, the primary, secondary, tertiary and higher order veins glabrous; abaxial surface glabrous, the indumentum caducous on the tertiary and higher order veins; 5-plinerved, including the tenuous marginals, innermost pair of secondary veins diverging rather symmetrically from the primary vein 0.5–0.6 cm above the base, areolae 0.9–1 mm, adaxially the primary and secondary veins impressed, the tertiary and higher order veins flat, abaxially the primary and secondary veins elevated, canaliculate to terete, the tertiary and higher order veins slightly elevated. Inflorescences an axillary and terminal dithyrsoid 16–18 cm long, including a terete peduncle 6–7 cm long, pendant, laxly and divaricately branched from the peduncle apex, paired or solitary in the axils of upper leaves; bracts 0.3–0.4 × 0.15–0.2 mm, bracteoles 0.5–0.7 × 0.2–0.3 mm, linear-subulate, green-reddish, the indumentum caducous on both surfaces, deciduous to subpersistent on immature fruit. Flowers 5-merous on pedicels 0.5–0.6 mm long. Hypanthia at anthesis 1.9–2.1 × 1.5 mm, free portion of hypanthium 0.9–1 mm long, subcylindric to campanulate, bluntly 10- ribbed, greenish, the indumentum caducous becoming sparse, ridged on the inner surface, densely glandularpuberulent, some of the glands stalked with rounded-flattened heads, intermixed with a dense understory of sessile minute rounded glands, the torus adaxially glandular-puberulent, the glands with rounded-flattened and slightly furrowed heads. Calyx open in bud and persistent in fruit, whitish; tube 0.4–0.5 mm long, with the same vestiture as the torus adaxially and as the hypanthium abaxially; lobes 1.1–1.2 × 1.1 mm, depressed-rotund, the margin entire, the apex obtuse, glabrous on both surfaces; exterior calyx teeth 0.2–0.3 mm long, minute and bluntly triangular, inserted inframarginally at the base of the calyx lobes and not projecting beyond them. Petals 2.5–4 × 0.7–1 mm, oblong-lanceolate, the margin entire, the apex bluntly acuminate, white, glabrous on both surfaces, somewhat spreading at anthesis. Stamens 10; filaments 1–1.3 × 0.25 mm, whitish, glabrous; anther thecae 1.4–1.6 × 0.3–0.5 mm, oblong-lanceolate, bluntly acuminate at the apex, opening by one dorsally inclined pore 0.1 mm in diameter, whitish; connective darker than the thecae when dry, its prolongation and appendage 0.25–0.45 mm long, the appendage subulate, bluntly acute to obtuse at the apex, bearing conspicuous glandular trichomes at the apical edge, the glands with flattened rounded heads, slightly furrowed and minutely stalked, the stalks subulate. Ovary 5- locular, 9/10 to completely inferior, 1.2–1.4 mm long at anthesis, the apical collar 0.2–0.3 × 0.4 mm, conic-truncate, densely glandular-puberulent with the same kind of glands as the torus adaxially and the staminal appendage; style 5–6 mm long, moderately narrowed distally (i.e. tapering), white, glabrous; stigma expanded truncate to capitellate. Berries 6.5–7.5 × 7.5–8.5 mm when dry, globose and slightly oblate, orange to red when ripe, the hypanthial indumentum subpersistent at maturity. Seeds 0.3–0.35 × 0.21–0.24 mm, ovoid, angled; lateral and antiraphal symmetrical planes ovate, the highest point toward the chalazal side; raphal zone suboblong, ca. 90 % the length of the seed, ventrally expanded toward the micropyle; appendage absent but a small protuberance present; individual cells elongate, some anticlinal boundaries channeled, others raised, undulate, with U-type patterns; periclinal walls flat, microrelief verrucose to somewhat striate.

Additional specimens studied:— ECUADOR. Azuay: 21 km SE of Troncal, track from Zuchay to manta Real, 1.5 km above Manta Real, above Río Patúl , 2°34'S, 79°21'W, 450 m, 14 August 1997, Lewis et al. 3450 ( NY) . Pichincha: Santo Domingo de los Colorados to Quito , ca 15 km Eof Santo Domingo, in woods along small stream Sof road, 0°20'S, 79°2'W, 700 m, 6 December 1986, Hammel & Trainer 15884 ( MO) . Los Ríos: Río Palenque B.R., km 56 Road Quevedo-Sto, Domingo , Along trail 1 about 200 m from junction with entrance road, 150–220 m, 5 March 1977, Dodson 6650 ( MO) .

Illustration: et al. None found.

Common names and documented uses:— None recorded.

SYSTEMATICS OF THE OCTOPLEURA CLADE OF MICONIA

Phytotaxa 179 (1) © 2014 Magnolia Press 107

Habitat, distribution and ecology:— This rarely collected species is known only from humid lowland Andean forests on the Pacific slope of Ecuador ( Fig. 13 ), at 150–700 m. It has been collected at the Río Palenque Biological Station (Los Ríos) and in primary forest remnants on steep slopes along the Santo Domingo de los Colorados—Quito Road (Pichincha). The most recent collection is from the province of Azuay, representing the first record for this area in Ecuador .

Phenology:— Collected in flower and fruit in August, October and December; only in fruit in March.

Etymology:— The specific epithet refers to the area where this species grows, close to the Palenque River in Ecuador.

Discussion:— This species appears to be most closely related to M. bensparrei . Both are characterized by sessile, amplexicaul, oblong-elliptic leaves, and the brownish asperous indumentum on vegetative parts and hypanthia. In describing these two species in the same publication, Wurdack (1978a) differentiated them principally by their venation (5-plinerved vs. 7- or 9-plinerved in M. bensparrei ) and differences in floral size (larger in M. bensparrei ). He mentioned other characters, including pedicel size and inflorescence position. However, the inflorescences are terminal (eventually pseudolateral) in both, and the pedicel size is so small in both taxa that these differences seem insignificant. Asingle flower was dissected from the little available material in the fragment folder of the holotype. It has a well-developed, glandular apical collar on the ovary which Wurdack made no mention of. This glandular ovary collar is also present in M. bensparrei . The differences suggest that these two species may be conspecific but we have refrained from combining them until more collections come to light.

Conservation status:— Endangered EN B2ab(iii). This species is endemic to the western foothills of the Ecuadorean Andes, where habitat destruction is the major threat ( Cotton & Pitman 2004). It is protected in the Río Palenque Biological Station (Los Ríos).

Figures

FIGURE 13. Distributions of Miconia bensparrei and M. palenquensis, M. biolleyana, M. boekei, and M. bractiflora.