Pleurothallis ecomingae M. Jiménez, Baquero & Mark Wilson, 2018

Wilson, Mark, Jiménez, Marco M., Jost, Lou, Kay, Andreas, Frank, Graham & Baquero, Luis E., 2018, A new species of Pleurothallis (Orchidaceae, Pleurothallidinae) from northwestern Ecuador with affinities to both subgenera Ancipitia and Scopula, Phytotaxa 343 (3), pp. 249-258 : 252-253

Pleurothallis ecomingae M. Jiménez, Baquero & Mark Wilson , sp. nov. ( Figs. 5–7 ).

This species has flowers similar to those of the yellow-flowered P. wielii of the “ P. crocodiliceps (P. arietina-P. nelsonii)” complex. P. ecomingae can be easily distinguished from P. wielii by the fascicle of single-flowered flower-bearing stems near the apex of the narrowly lanceolate leaf versus few single-flowered flower-bearing stems emerging from the base of an ovate leaf in P. wielii .

Type:— ECUADOR. Carchi: Chical-El Carmen road, Km. 18-Km. 19, 2228 m elevation, 2 nd April 2016, Baquero 3106 (holotype: QCNE!).

Plant medium in size, epiphytic, caespitose; roots flexuous, thin, densely fasciculate. Ramicauls slender, erect to suberect, terete, 16.6 cm long, with a tubular papyraceous sheath below the middle, 3.7 cm long and two others at the base. Leaves suberect, sessile, thinly coriaceous, oblanceolate to narrowly elliptical, acute, 16.6 × 1.7 cm, the base narrowly cuneate, decurrent on the ramicaul. Inflorescence a fascicle of solitary, successive flowers borne from a reclining scarious spathaceous bract near the apex of the leaf, 8 mm long; peduncle filiform, ascending, 9 mm long; floral bract tubular, 6 mm long; pedicel ascending, 14 mm long; ovary arcuate, 9 mm long. Sepals dark yellow spotted with chocolate brown near the base, glabrous, cellular-glandular; dorsal sepal ovate-triangular, 12 × 3 mm, semi-erect, tubular, concave at the base, narrowing over the middle, obtuse at the apex; lateral sepals completely connate into a synsepal, similar to the dorsal sepal, 10 × 4 mm. Petals dark yellow, paler than sepals, with a few chocolate brown spots at the base, cellular-glandular, oblong, obliquely triangular above the middle, apically acute, 10 × 2 mm. Lip 2 × 1 mm, chocolate brown, white at base and margins, delicately hinged to the base of the column by a flexible strap, three lobed, obpentagonal; middle lobe ovate-cordiform, thick, convex, densely pubescent, pilose at margin, with a pair of longitudinal swollen calli beginning from the basal lobes to the apex, small orifice above the cleft, obtuse apex; basal lobes narrowly falcate-triangular, densely pubescent, pilose on the outer margin; the base elevated, truncate, hinged behind a conical callus at the base of the column. Column arcuate, semiterete, pedestal like, without foot, 3 mm long; anther and stigma apical. Pollinia two, 0.7 mm long.

Etymology:— Named after Fundacion EcoMinga, a science-based Ecuadorian conservation organization, which has established the Dracula Reserve in the Chical region of northwest Ecuador.

Comments:— This species is vegetatively similar to the narrowly lanceolate-leaved species from subgenus Scopula , including P. aspergillum , P. garayana , P. ottocarii , P. ruscaria , P. scoparum and P. tetroxys ( Fig. 1 ). P. ecomingae can be easily distinguished from all of these species by the yellow and chestnut flowers with a minute, pubescent, tri-lobed lip in which the lateral lobes are elaborated into ‘horn-like’ projections, with a minute orifice in the apical region of the central lobe, as in species of the “ P. crocodiliceps (P. arietina-P. nelsonii)” complex.

Distribution and habitat:— The type locality for P. ecomingae is in very humid cloud forest at an elevation of 2,228 m, between Km. 18 and Km. 19 of the Chical-El Carmen road, in Carchi Province, near the Ecuador-Colombia border ( Fig. 2 ). P. ecomingae has also been observed growing further south near Rio Gualpi at an elevation of ~ 1,900 m. To our knowledge P. ecomingae has not been observed in adjoining areas of Ecuador or Colombia and may be endemic to this area of Carchi Province near Chical.

Conservation status:— Neither of the known localities for P. ecomingae occur in protected areas and it is not yet known whether P. ecomingae occurs within the borders of any of the parcels of the Dracula Reserve or in the Bosque Protector Golondrinas. Further, the whole area is under mining concession ( Roy et al. 2018), and since the opening of the Chical-El Carmen road there has been substantial deforestation of adjacent areas for cattle ranching, suggesting that the species is at high risk from deforestation. However, until additional surveys can be completed the species should probably be listed as “data deficient” (DD) according to IUCN criteria.

Figures

FIGURE 1. Pleurothallis species from subgenus Scopula with narrowly lanceolate leaves and a near-apical fascicle of single-flowered peduncles: A. P. aspergillum; B. P. garayana; C. P. ottocarii; D. P. ruscaria; E. P. scoparum; and F. P. tetroxys. (A, B, D, E, F and G courtesy of Missouri Botanical Garden; C. Courtesy of Systematic Botany).

FIGURE 2. Distribution map of Pleurothallis species in subgenus Scopula prepared with collection locality data from Tropicos and Luer (1989) using ArcGIS. Type locality of P. ecomingae indicated by a star. (Prepared by Graham Frank and Mark Wilson.)

FIGURE 5. Lankester composite digital plate of P. ecomingae. A. Flower (side view); B. Flower (top view); C. Leaf and apical ‘tuft’ of single-flowered peduncles; D. Flower (front view); E. Column, anther and lip (front view); F. Lip. (Prepared by Mark Wilson from photos by Francisco Tobar Suárez and Andreas Kay.)

FIGURE 6. Drawing of P. ecomingae. A. Flower (front view); B. Lip (side and front view); C. Whole plant; D. Column and lip (side view). (Prepared from the holotype by Luis Baquero.)

FIGURE 7. P. ecomingae in situ near Rio Gualpi site. A. Plants growing epiphytically on tree trunks amongst ferns and other flora; B. Leaf and apical ‘tuft’ of single-flowered peduncles in natural orientation; C. Leaf and apical ‘tuft’ of single-flowered peduncles lifted to show inside of flowers; D. Two flowers (front view). (Photographed in situ by Andreas Kay.)