Epidendrum yanatilense Damian & Hágsater, 2016

Damián, Alexander & Hágsater, Eric, 2016, Epidendrum Yanatilense (Orchidaceae: Laeliinae), A New Species, From Cusco, Peru, Phytotaxa 246 (4), pp. 287-292 : 288-290

Epidendrum yanatilense Damian & Hágsater , sp. nov. ( Fig 1 )

Similar to Epidendrum pucunoënse ( Hágsater & Dodson 2001: t. 476) from which it differs by its small habit (5 cm vs. larger plants 17- 32 cm), sepals oblong-obovate (vs. oblong-lanceolate), petals apex rounded (vs. acute), calli rhomboid (vs. rounded), inwards (vs. erect), without mid-rib in the middle (vs. short keel in the middle) and distribution, Peru (vs. Ecuador).

Type:— PERU. Cusco: Provincia de Calca. Distrito de Yanatile 4 km from Santiago valley, 12°34’31.74”S, 72°25’24.05”W, 2,450 m elev., 27 May 2015, A.Damián & U. Huaycho 0300 (Holotype MOL!).

Herb to ca. 5 cm tall, epiphytic, erect, sympodial, caespitose. Roots basal, fleshy, thin. Stems 2.5 cm long, simple, cane like, ancipitose. Leaves 5, equally distributed throughout the stem, distichous, alternate, articulate, generally erectspreading, embracing; sheaths tubular infundibuliform, laterally compressed; blade 7–9 × 1 mm, ovate to oblongovate, obtuse, acuminate, coriaceous, margin entire. Spathe 1, ca. 11 × 1 mm, nearly parallel-sided, acute, covering half the peduncle, margin papillose. Inflorescence 1.8 cm long, apical, racemose, sub-erect, lax-flowered, with 2 flowers; peduncle 1.2 cm long, rachis 0.6 cm long. Floral bracts 3 × 1 mm, shorter than the ovary, acuminate. Ovary 6 mm long (in fruiting stage), terete. Flowers simultaneous, non-resupinate, color greenish brown, fragrance not registered. Sepals partly spreading, ovate, acute to acuminate, thickened towards the apex, 3-veined, the mid-vein prominent; dorsal sepal 4 × 1.5 mm, oblong-obovate, obtuse, with a mucro at the apex; lateral sepals 3.5 × 1.4 mm, oblong-elliptic, oblique, aristate, with a prominent dorsal keel. Petals 3.5 × 0.3 mm, reflexed, linear, apex rounded, 1-veined. Lip 2.0 × 2.5 mm, united to the column, 3-lobed, spreading, forward; bicallose, calli prominent, laterally compressed, laminar, rhomboid, leaning inwards and nearly touching each other; lateral lobes 0.8 × 1.0 mm, prominent, semi-orbicularquadrate, projecting at a 45° angle, margin entire; mid-lobe 1.4 × 1.0 mm, triangular, acute. Column 2.5 mm long, short, thick, straight. Clinandrium reduced, margin entire. Nectary narrow, without penetrating the ovary. Anther not seen. Pollinia not seen. Capsule not seen.

Distribution and habitat:— Know only from the type collection in the province of Calca, Cusco department, southern Peru at 2,400 m ( Fig. 2 ). Epiphyte on a Weinmannia Linnaeus (1759: 997) tree, growing together with Trichosalpinx teaguei Luer (1997: 82) , Trichosalpinx cedralensis ( Ames 1923: 18) Luer (1983: 394) , and Barbosella cucullata ( Lindley 1845: 108) Schlechter (1918: 261) , in a cloud forest dominated by Cyathea Smith (1793: 416) , Elleanthus Presl. (1827: 97) and Lycopodium Linnaeus (1753: 1100) species, and codominated by Ericaceae shurbs. Canopy is up to 15 m high, represented by Podocarpus L’Hér. ex Pers. in Persoon (1807: 580) trees.

Phenology:— Know to flower in May.

Conservation:— The species is threatened by its restricted distribution (know from only one locality). Moreover, its habitat is severely affected by the establishment of a coffee plantation. According to the IUCN Red List Categories and Criteria (2010) E. yanatilense would qualify as Critically Endangered CR (criteria B1a, B1b(i)). However, further field studies are required to attain an objective assessment of its conservation status.

Etymology:— In reference to the district where the type was collected, Yanatile, Calca province, Cusco department.

Discussion:— Epidendrum yanatilense is similar to E. pucunoënse , within the alpicolumn group, which is characterized by the simple, cane-like stems, long, narrow 1–2 spathaceous bracts, fox-tail-like inflorescence and numerous flowers with fleshy lip, triangular mid-lobe and roundish lateral lobes. The new species is recognized by the very small plant, to ca. 5 cm tall, flowers are non-resupinate, small, dorsal sepal 4 mm long, and the lip is 3-lobed, with rounded lateral lobes and a triangular mid-lobe; calli two, large, laminar, rhomboid, leaning inwards so as to form a cuniculus in front of the entrance to the nectary. Epidendrum pucunoënse has larger plants, 17–32 cm tall, and numerous flowers on a raceme, the flowers are yellow-brown, the lip yellow, the calli are laminar, rounded, erect, with a short, thickened mid-rib in the middle; clinandrium is prominent, funnel-shaped, emarginate. Moreover, the calli of the new species are leaning inwards, laminar and it does not appear to have a thickened short mid-rib in between the calli, as is usual in all species of the E. alpicolum ( Reichenbach 1854: 2) group, including E. pucunoënse .

Among Peruvian species of Epidendrum , E. yanatilense is distantly similar to E. imanoenum ( Kränzlin 1906: 37) ( Santiago & Hágsater 2009) . However, the latter resembles a different group (Scabrum group), which is characterized by a branching stem with infundibuliform, rugose, leaf sheaths and carrying acute, aristate, lanceolate leaves blooming on a short, thin, capitate inflorescence and flowers with a bicallose lip. Although the calli of the new species is reminiscent of E. inamoenum , with two laminar calli so as to form a canal in front of the entrance to the nectary; it has a monopodial plant habit, branching above, lacks any spathe, and is in every way much larger, stems to 50 cm tall. Moreover, small Epidendrums, such as E. yanatilense (<10 cm tall) are not uncommon within the genus. For example, E. miserrimum ( Reichenbach 1855: 15) or E. crassum ( Schweinfurth 1952: 141) are quite frequent and have a wide distribution range. In addition, among the 12 Epidendrum species for Calca-Cusco ( Tropicos, 2016), from where E. yanatilense is here reported, E. physopus ( Kränzlin 1905: 87) and E. repens ( Cogniaux 1909: 137) have reported small sizes (12 cm long). Nonetheless, none of them shares the distinct set attributes of E. yanatilense , i.e. small plant (5 cm tall); 3-lobed lip; and two, laminar, rhomboid, leaning inwards calli.

Approximately 115 Epidendrum species have been previously recorded from Cusco ( TROPICOS, 2016), most of them reported at the northern provinces of La Convención, Urubamba and Calca, where mountain rainforest is one of the dominant habitats. However, the province of Calca, represents only 11% of the total richness of the genus in the region. This scenario might be favored by any of the following reasons (1) the area surface of the province, being 4,000 km 2 (vs. 30,000 km 2 of La Convención); (2) lack of specialized botanical exploration in the zone; and (3) the severe consequences of deforestation. A good example of these factors and its local impact on reporting biodiversity is E. yanatilense . We believe that the dearth of specialized orchid exploration; like what occurs intensely on nearby sites like Macchu Picchu with 325 km 2 (Urubamba), and where so far 372 orchid species has been registered ( Collantes et al. 2007); may have lead to an underestimation of biodiversity in the area and eventually the existence of overlooked groups of plants, especially those inconspicuous such as E. yanatilense . Furthermore, Calca, according to local information, represents one of the most deforestated provinces of Cusco (unpbl. data). Forest degradation for the establishment of agricultural fields such coffee or coca plantations are well spread over the Yanatile’s mountains ( Figure 2A ), and play a critical role in loss of local biodiversity on similar ecosystems ( Young & Leon 1999). In fact, we failed to find any additional populations of E. yanatilense . Instead, we found a recently degraded area just half an hour from the type collection of the new species ( Figure 2B ). Therefore, it is highly probable that our specimen represents the last individual on that particular location.

Figures

FIGURE 1. Epidendrum yanatilense Damian & Hágsater. A. Habit. B. Flower. C. Dissected perianth. D. Column and lip, lateral view. E. Column, ventral view. (from A. Damian 0300, MOL).

FIGURE 2. Habitat of Epidendrum yanatilense. A. Yanatile, deforestation is leaving the upper hills near town denuded due to coffe and coca plantations. B. Degraded area close to where the type specimen was collected.Arrows show the exact locality where E. yanatilense is here reported. Photographs by A. Damian.