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Introduction
The species of Scaphosepalum Pfitzer (Pleurothallidinae) are recognized by the non- resupinate flowers and the connated sepals with osmophores at the base forming a deep and rounded structure with conspicuous sepaline tails in most of the species (Luer 1988). More than 50 species have been described many of them discovered in the past three decades (Luer 1988, 1991, 1992, 1998a, 1998b, 2000, 2009, Endara et al. 2011, Chase et al. 2015, Karremans 2016, Karremans et al. 2016, Valenzuela 2015, Baquero 2017).
Luer (1988) recognized some species-complexes with extensive geographical distributions and populations with similar morphological traits across the geographical range, like Scaphosepalum breve (Rchb.f.) Rolfe, Scaphosepalum odontochilum Kraenzl. or Scaphosepalum swertiifolium (Rchb.f.) Rolfe. Nonetheless, some years after his monograph of the genus, Luer described more species as Scaphosepalum martineae Luer, S. redderianum Luer, S. jostii Luer or S. globosum Luer, segregated from the species-complexes where they would originally fit (Luer 1988a, 1998b, 2009). Scaphosepalum. jostii and S. globosum, two species related to S. odontochilum, were considered distinct species; as well as S. martineae and S. redderianum (Luer 1998b, 2009). A similar case happens with a recently discovered new species of Scaphosepalum which is described here.
Another species, Scaphosepalum anchoriferum (Rchb.f.) Rolfe, which has a wide phenotypic variation among several populations (Luer 1988b), is mostly known from Costa Rica and Panama, except for a mention of the species for Ecuador by Luer (2003) without voucher specimen. Nevertheless, in north-western Ecuador, several plants of S. anchoriferum have been recently found, corroborating Luer´s observation. The new species mentioned above and S. anchoriferum were found growing sympatrically in a forest in north-western Ecuador. Notes on the new species and S. anchoriferum from north-western Ecuador are given here.
Materials and methods
Plants of Scaphosepalum luannae and S. anchoriferum were discovered and collected by the team of the Botanical Garden of Quito. These plants were cultivated by the Botanical Garden of Quito, where they were used for morphological comparisons, together with specimens preserved in alcohol. The flowers of the plants cultivated for more than 15 months shown no appreciable differences in morphology compared to those observed in the field when the specimens were collected.
Due to the small size of the flowers, measurements were largely conducted on the basis of photos with a 10 mm ruler and the open-source, image-processing program ImageJ (National Institutes of Health) downloaded from https://imagej.nih.gov/ (Lind 2012). The material was photographed with a ruler at the same focal distance. The photos were opened in ImageJ and 10 mm of the ruler were set as a scale. The program calculates the number of pixels to the given unit, providing measurements for the photographed objects.
Taxonomic treatment
Scaphosepalum luannae Baquero, sp. nov. (Fig.1‒4).
TYPE: Ecuador. Carchi: between Chical y El Carmen, 0°54’42.5” N 78°12’48.7” W, 1750 m, collected by Luis Baquero on 8th of May 2016, LB 3121 (holotype, QCNE).
Diagnosis
Scaphosepalum luannae is similar to S. swertiifolium but it differs in the smaller (7-10 vs. 8-21 cm long), dark green, reflective leaves (vs. light green, non-reflective) conspicuously nerved at the abaxial surface (vs. not conspicuously nerved); the shorter ramicauls (3.5-5.0 vs 4-10 cm long); the well-developed, subquadrate, reflexed osmophores of the lateral sepals (vs. transversely lunate, markedly divergent); the sub-quadrate petals with a callous lobe at the base of the columnar margin (vs. ovate, oblique, ecallose), the lip truncate at the base, elobulate (vs. provided wit minutely auricles); and the flat and oblong hipochile (vs. shallowly concave, more or less oblong in S. swertiifolium) (Fig. 3-4).
Description
Plant epiphytic, densely caespitose, to 10 cm tall. Roots slender, 0.6 mm in diameter. Ramicauls erect, slender, 2.0-3.5 cm long, enclosed by 3 sheaths. Leaf elliptic, acute, sub-erect, thinly coriaceous, markedly veined at the abaxial side, 7-10 cm long including the petiole, 3.5-5.0 cm wide, cuneate below into a slender, channeled petiole 2 cm long, dark green adaxially, glaucous green abaxially, conspicuously shiny- reflective at both sides. Inflorescence a loose, flexuous, successively several to many-flowered raceme from low on the ramicaul, 5-7 cm long, each flower borne on a slender, glabrous, horizontal peduncle 2.5-4.0 cm long. Floral bracts thin, shorter than the pedicel, conduplicate, acuminate, bristle-pointed, 3 mm long. Pedicel 4 mm long. Ovary ribbed, 2.5 mm long. Sepals cream, suffused with pink spots which turn into pink stripes towards the junction of the lateral sepals, margins ciliate, with two carinae (a high and a low carina); dorsal sepal tricarinate, ovate, concave in the basal quarter, 12.0 × 2.5 mm in natural position, narrowly tubular with revolute margins, the apical three-fourths rose to pink; lateral sepals trapezoid, diverging, prickly, thick, reflexed, terminating in a straight, white tail 10-15 mm long, connate 8 mm, with an oblong, concave lamina 9 mm long unexpanded, the apical portion of each sepal suffused with pink and rose dots; cushion (osmophore) 4 × 3 mm (2 × 3 mm in the shorter sides of the trapezium), the total length of each lateral sepal including the tail 19-24 mm. Petals sub-quadrate, cream suffused with yellow, columnar margin with a round projection, labellar margin glandulose in texture, suffused with red stripes and blotches, 3.0 × 2.5 mm. Lip purple, oblong- subpandurate, reflexed near the middle, 2.2 × 1.0 mm; the epichile narrowly obovate, slightly ciliate at the edge; the disc with a pair of tall, erect, keeled lamellae above the middle; the hypochile rectangular, shallow, the base truncate. Column white suffused with rose at the apex, arcuate, semiterete, slender, 3.5 mm long, with two wings in the middle, with a short, 0.5 mm long foot. Pollinia 2, yellow. Fruits and seeds not observed.
Eponymy
This species is named in honor of Luanne Lemmer of Washington State, USA. Luanne, her husband Eric Veach, and their two sons, Malcolm and Nigel, are passionate supporters of conservation and have given important help to Rainforest Trust and EcoMinga for the establishment of the Dracula Orchid Reserve, which now protects this species.
Other studied material
Ecuador. Carchi, Cerro Oscuro, 0°54’42.5”N 78°12’48.7”W, 1818 m, cultivated at the Jardín Botánico de Quito, LB 3132 (QCNE-spirit).
Distribution
This species is known from three areas close to Chical in north-western Ecuador. Scaphosepalum luannae was first found by the author in a remnant of cloud forest around km 9 of the Chical- El Carmen road. Eventually, more plants where found growing in Cerro Oscuro very close to Chical, and afterwards in the Peñas Blancas ridge, within sight of the mountains of Colombia. It would not be surprising if the species is eventually found growing in adjacent regions of Colombia.
Habitat and ecology
Scaphosepalum luannae grows as an epiphyte in moist cloud forest simpatrically with S. decorum Luer & Escobar, S. cimex Luer & Hirtz, S. ophidion Luer, S. reptans Luer & Hirtz, S. swertiifolium and the recently discovered S. zieglerae Baquero. No intermediates of S. luannae and S. swertiifolium have been found at the locality where they grow sympatrically, which might suggest both species have independent pollinators. In addition, the only known population of S. zieglerae was found very close to the type locality of S. luannae (Luer 1988, Luer 2009, Baquero 2017).
The most similar species to Scaphosepalum luannae is S. swertiifolium mainly due to the long sepaline tails. Although, there are some color variations in S. swertiifolium (even a big pink big flowered form from Colombia), in all the geographic variations and sub-species of this widely distributed species, the shape and structure of the lip and petals are always different from those of S. luannae. The sub-quadrate petals of S. luannae have a tooth-like, conspicuous, rounded and callous projection at the base of the columnar margin that is absent in any variation or subspecies of S. swertiifolium. The lip of S. luannae has an oblong and flat hypochile with a truncate, elobulate base, while in S. swertiifolum the hypochile of the lip is suborbicular and shallowly concave, always minutely bilobulate at the base (Fig. 3). Apart from the morphology of the lip, petals, and osmophores, S. luannae is also immediately distinguished from S. swertiifolium by the shiny surface and dark olive color of the leaves, which are always smaller in the former species. Another unique feature of S. luannae is the abaxial side of the leaves with strongly marked veins, which is not seen in any other species in the genus (Fig. 4).
Scaphosepalum anchoriferum in Ecuador
Scaphosepalum anchoriferum was discovered in the area of Peñas Blancas, Carchi province of north-western Ecuador, close to the border with Colombia. It grows sympatrically with S. luannae, S. cimex and S. swertiifolium. The flowers are brightly colored and with a relatively shallow synsepal compared to forms found in Costa Rica and Panama (Luer 1998).
Considering that Scaphosepalum bicolor Luer is the most similar species to S. anchoriferum found in Colombia, it is most probable that S. anchoriferum will eventually be discovered in this country as well. The shape of the flower and the bright colored sepals of the Ecuadorian variety seems to differ from the typical S. anchoriferum. Nevertheless, the lips of plants from Panama and Ecuador are identical in structure and shape when compared. Both varieties have lips which are oblong-subpandurate, dilated in the middle third, with a pair of denticulate lamellae, the epichile orbicular, serrulate, the hypochile more or less oblong, truncate, minutely bilobulate (Fig. 5). Also, the habit of the plants and consistency of the leaves (coriaceous, “harder” than in other species like S. swertiifollium) are the same in the plants from Ecuador and Panama.
Scaphosepalum anchoriferum (Rchb.f.) Rolfe (Fig. 5). Ecuador. Carchi: between Chical y El Carmen, 0°59’24.0”N 78°13’14.9”W, 1636 m, collected by Luis Baquero et al. on February 26, 2017, LB 3128 (holotype, QCNE).
Plant epiphytic, densely caespitose, to 10 cm tall. Roots slender, 0.5 mm in diameter. Ramicauls erect to sub-erect, slender, 1-4 cm long, enclosed by 3 sheaths. Leaf elliptic, subacute, erect to sub-erect, thinly coriaceous, markedly veined at the abaxial side, 7-15 cm long, 2.0-5.0 cm wide, gradually narrowed below in to a slender, channeled petiole 1-4 cm long. Inflorescence a congested, successively several-flowered raceme from low on the ramicaul, up to 8 cm long, born by a slender, smooth, horizontal to descending peduncle up to 10 cm long. Floral bracts thin, 3 mm long, 2-7 mm long. Ovary ribbed, 2 mm long. Sepals yellow-green, suffused with red-purplish spots, the margins ciliate. Dorsal sepal yellow-green, tri-carinate at the outer surface, ovate, acute, concave below the middle, narrowed and with revolute margins above the middle, 10 × 4 mm expanded. Lateral sepals yellow spotted with red dots, concave, the lamina elliptic, 10.2 × 6.1 mm, connate 10 mm, the apical half of each lateral sepal occupied by a thick, well-developed, triangular, microscopically densely pubescent cushion 4 × 6 mm, the obtuse, diverging apices contracted into a slender, decurved tail 5 mm long. Petals yellow, marked with red-purple, ovate, acute, more or less dilated on the labellar margin, 4.5 × 2.5 mm. Lip yellow spotted with red-purple, oblong-subpandurate, 3.5 × 2 mm, reflexed and dilated near the middle, with a pair of denticulate lamellae extending from the base to one third of its length, the epichile orbicular, serrulate, the hypochile more or less oblong, truncate, minutely bilobulate. Column yellow-green, suffused with red, semiterete, slender, 4 mm long, broadly winged above the middle, with a thick, 2 mm long foot. Pollinia 2, yellow. Fruits and seeds not observed.
