Introduction

The genus Lepanthes Sw. comprises more than 800 species (^{Luer 1996}, ^{Farfán et al. 2003}) and is one of the largest orchid genera. Species of Lepanthes occur from southern Mexico through the Antilles to Bolivia and Brazil (^{Luer & Thoerle 2010}) and from 100 up to 3300 m elevation (^{PérezEscobar et al. 2013}). In Peru, the number of reported Lepanthes species has increased dramatically during recent decades: 14 species of Lepanthes were recorded by ^{Schweinfurth (1958}, ¹⁹⁷⁰), but later increased to 46 species as reported by ^{Brako & Zarucchi (1993}) and ^{Ulloa Ulloa et al. (2004}). At this moment, the Kew World Orchid Checklist (^{Govaerts et al. 2015}) and tropiCos (www.tropicos.org) record 55 and 63 Lepanthes species for Peru, respectively. This number, however, would be a low estimation of the actual diversity in the country, since there is not yet any study of the genus in Peru. The monumental work of Carlyle A. Luer is mainly based on Ecuadorian and Colombian specimens; thus, in Ecuador and Colombia there are recorded more than 300 species each (Farfán et al. 2003, Thoerle & Hirtz 2015). If the number of the known species decline at the limits of Lepanthes distribution (^{Thoerle & Hirtz 2015}), Peru may eventually present more species than Bolivia; however, the last revision of Bolivian Lepanthes recorded 67 species (Luer &Thoerle 2010). New species and records are expected to significantly increase the diversity of Peruvian Lepanthes as exploration continues.

During explorations in the Machu Picchu Historical Sanctuary (Czusco, southern Peru), the Inka Terra Association team discovered plants of a Lepanthes species with flowers unusual in their size and morphology, later determined to be Lepanthesmiraculum Luer & R. Vásquez. This species was only known from a few collections in the province of Chapare (Cochabamba, Bolivia), and no further details have been given about this species since its publication (Luer 1983). Here, we report L. miraculum as a new addition to the orchid flora of Peru and provide details of the new population, including an updated description and distribution map, and a line drawing and in situ photographs based on the Peruvian specimens.

Material and Methods

Field work in Machu Picchu was conducted in April 2013. The specimen of Lepanthesmiraculum was collected and preserved in spirits. Micromorphological characters were studied under stereomicroscope. Herbarium specimens from USM and SEL were examined (acronyms follow the Index Herbariorum). The software DIVA-GIS (Version 7.5) and Irfanview (Version 4.33, Irfan Skiljan) were used to prepare the distribution map.

Taxonomic treatment

Lepanthesmiraculum^{Luer & R. Vásquez. Phytologia 54: 353. 1983}. (Figs. 1, ²).

Figure1.  Lepanthes miraculum. A. Habit. B. Flower, frontal view. C. Dissected flower with details of the sepaline margins. D. Detail of a carina from the exterior of the dorsal sepal. E. Petals, lip, and column, frontal view. F. Right petal, frontal and lateral views. G. Ovary, lip, and column, with surface details, lateral view. H. Lip and column, ventral view. Drawn from B. Collantes et al. 178 (USM) by B. Collantes. 

Figure2. Lepanthes miraculum in situ. A. Habit. B. Plant with inflorescences. C. Flower, frontal view. D. Closeup of the flower. Photographs by B. Collantes. 

TYPE: Bolivia. Cochabamba, Prov. of Chapare, epiphytic in cloud forest between Cochabamba and Villa Tunari, elev. 2500 m, 22 Jan. 1980, C. Luer, J. Luer & R. Vásquez 4906 (holotype: SEL!).

Epiphytic herb. Plant medium in size for the genus, 13-21 cm tall including the inflorescence, caespitose. Roots fuchsia, relatively coarse, 0.52-0.85 mm diameter. Ramicauls slender, erect to suberect, 3.0-11.0 cm long, enclosed by 6-11 ciliate or densely pubescent lepanthiform sheaths with ciliate, markedly dilated ostia. Leaf dark green to grayish green, suffused with purple or shiny green beneath, erect, coriaceous, elliptical, subacute, 2.0-3.0 × 0.9-1.2 cm, the base cuneate into a petiole 2.0-5.0 mm long. Inflorescence 1-3 fractiflex, successively flowered racemes bearing 2-13 flowers, borne above the leaf, up to 11 cm long including the slender, terete peduncle 2.5-4.0 cm long; floral bracts 1.5-2.0 mm long, ciliate; pedicels 2.5-4.0 mm long; ovary 6-winged, wings irregularly erosedentate, 1.5-2.0 mm long. Flowers color of sepals dark brownish orange to dark red, veins brownish, margins orange; petals orange with golden yellow apices and anterior margins, or red; the lip dark, dull pink or bright purple; the column rose-purple; sepals spreading, noticeably papillose to shortly pubescent internally, externally carinate along the veins, carinae with irregularly erose-dentate margins with digitiform projections; dorsal sepal with margins erose-dentate with digitiform projections, triangular-ovate, the apex acuminate into a cauda ca. 5 mm long, 10.5- 14.0 × 6.5-7.0 mm including the cauda, 3-veined; synsepalum with margins erose-dentate with conic apices, some with filiform projections, broadly ovate, basally concave, 11.5-14.0 × 8.5-10.0 mm including the caudae, with the distal third (ca. 4 mm) free, the apices acuminate into short caudae, 6-veined; petals transversely bilobed, the upper lobe reflexed, asymmetrically subcordate expanded, with short and long cilia, 1 mm in diameter expanded; the lower lobe narrowly triangular with cilia longer at the base, shorter toward the apex, 3.0-3.5 × 1.0 mm; lip bilaminate, the blades oblong-subsigmoid, 1.75-2.0 mm long, glabrous except for short cilia at the narrowly obtuse, inverted apices, the bases rounded, everted, with conicdigitiform papillae, the connectives broadly cuneate, connate to the column near the middle, the sinus obtuse with a broad, membranous, retuse, ciliate appendix in contact with a foot-shaped, clavate appendage from the stigma; column 2.0-3.0 mm long, the apical half dilated, the shaft microscopically papillose, terete, extremely slender; anther dorsal, stigma ventral; pollinia not observed.

Additional specimens. Peru. Cusco: Prov. Urubamba, Distr. Machu Picchu, Santuario Histórico de Machu Picchu; Pampaccahua, km 90 de la vía férrea CuscoMachu Picchu, Sector El Palomar [bosque anexo a las inmediaciones del nevado Huaqayhuillca], elev. ca. 3,000 m, B. Collantes, J. Ochoa & C. Soto 178, 12 Apr. 2011 (USM!). Bolivia. Cochabamba: Prov. of Chapare, epiphytic in cloud forest between Cochabamba and Villa Tunari, elev. 2,600 m, 26 Nov. 1978, C. Luer3490 (SEL); same area, collected by B. Wuerstle, elev. 2,700 m, 13 Jan. 1981, C. Luer5662 (SEL); Pampa Tambo [in the department of Cochabamba, not Potosí], elev. 2,800 m, 24 Dec. 1979, R. Vásquez 234 (SEL).

Etymology: From the Latin miraculum, "a marvel," referring to the features of the flower.

Distribution and ecology. The species is known from two disjunct areas (Fig. 3). The earlier collections are from the Province of Chapare (central Bolivia) and the newest is from the high mountains of the Machu Picchu Sanctuary (southern Peru). Plants of Lepanthesmiraculum occur in cloud forests at elevations from 2500 to 3000 m. The present report extends its distribution by ca. 800 linear km northward. Chapare and Machu Picchu cloud forests may formerly have been linked since another orchid species, Vasqueziellaboliviana Dodson, which also has a very restricted distribution, was recorded to be present only in the same two areas (^{Jenny 2011}). In Peru, plants of L. miraculum were observed growing on exposed trunks and branches of Polylepyspauta Hieron. (Rosaceae), which is the dominant tree species in the newly recorded habitat. An additional population was found inside the Machu Picchu Historical Sanctuary, on Cerro Poques, by the Inkaterra Association team (C. Soto 2013, pers. comm.).

Figure 3 Geographical locations of Lepanthes miraculum (triangles) in Peru and Bolivia. Gray scale indicates elevation (white [0 m] to dark gray [6,500 m]). Produced by Carlos Martel. 

Phenology. The population found in Peru flowers from March to April, whereas the collections from Bolivia have been recorded to bloom from November to January.

Conservation status. This species is presently known from only two places. The populations occurring in Bolivia are especially endangered and the species may even be extinct (^{Vásquez et al. 2003}). The populations found in Peru occur inside a protected area (the Machu Picchu Historical Sanctuary); nevertheless, anthropic activities may imperil its small populations. According to the IUCN Red List (^{IUCN 2014}), it can be listed as critically endangered (CR, criterion B1/extent of occurrence and C1/small population size and decline).

Lepanthesmiraculum belongs to the section Lepanthes subsection Lepanthes (Luer & Thoerle 2010). The flowers are large for the genus, but most unusual are the folded petals and the long, thin column with the broad connectives of the lip connate at about the middle. The specimens found in Peru present a ramicaul enclosed in densely pubescent lepanthiform sheaths similar to those of L.pubicaulis C. Schweinf, rather than less densely ciliate like those of the Bolivian specimens. The flowers from the two areas also vary, those from Peru having a flower with larger sepals (14 mm long vs. 10.5-11.0 mm long in the Bolivian specimens) that are minutely but visibly papillose internally, rather than shortly pubescent. The color of the flowers differs: sepals of the Peruvian individuals are brownish orange to dark red, the petals orange and golden yellow, whereas the Bolivian ones are red to dark red, and red, respectively.