Epidendrum choccei M.E.Acuña, Hágsater & E.Santiago, 2019

Acuña-Tarazona, Margoth, Hagsater, Eric & Ayala, Elizabeth Santiago, 2019, Epidendrum choccei (Orchidaceae), a new species from Northern Peru, Phytotaxa 394 (1), pp. 98-104 : 99-101

Epidendrum choccei M.E.Acuña, Hágsater & E.Santiago , sp. nov. ( Figs. 1–2 )

Type: PERU: San Martin: Prov. Rioja, Distrito: Pardo Miguel Naranjos: Bosque de Protección Alto Mayo, Tepui andino con formaciones rocosas sedimentarias y parches arbustivos, 3343 m, 6 de junio 2017, M. Acuña, J. Edquen & R. Espinal 2129 (holotype: USM!, isotype: AMO!)

Diagnosis: This new species is similar to E. leptanthum Hágsater ( Hágsater 2018b: pl. 1677) by small plants with branches short and inflorescence apical racemose, arching nutant. However, E. choccei differs in pink flowers and lip widely ovate acuminate, base truncate, ecallose without keels.

Description: Terrestrial, sympodial, sub-caespitose, decumbent, flexuous herb, 45 cm tall. Roots 1 mm in diameter, fleshy, thin, basal, scarce. Stems 35–41 × 0.15–0.20 cm, cane-like, terete, scarcely branching above, branches 22–30 × 0.15–0.20 cm, the first 3–4 internodes covered by leafless sheaths 5–20 × 1.5–2.0 mm. Leaves 17–19 on primary stem, distributed throughout, erect, parallel to the stem, at flowering the upper half present; 13–15 leaves on the branches; sheath 20–21 × 0.15–0.20 mm, tubular, rugose; blade 27–34 × 3 mm, narrowly lanceolate, acute, coriaceous, margin finely crenulate, spreading when fresh, margin strongly revolute when dry. Spathe lacking. Inflorescence 6–10 cm, apical, racemose to paniculate, arching-nutant, can produce new racemes even when the previous raceme is still in flower; peduncle 11 × 2 mm, short, thin but not thread-like, with a large flat bract near the middle, 11 × 2 mm. Floral bracts 5–8 × 3 mm, progressively shorter, triangular, acuminate, shorter than the ovary, embracing. Ovary 4–5 mm long, thick, forming a wide 45–90° arch with the column, not inflated, minutely pustulate. Flowers 19 per raceme, successive developing together with the rachis, 2–4 open at once, deep pink, the lip always turned towards the rachis, fleshy, disc of the lip white, column white at apex, green towards the base; without fragrance. Sepals partly open, 3- veined, dorsal surface slightly pustulate, the margin therefore slightly undulate; dorsal sepal 8.3 × 2 mm, narrowly lanceolate-elliptic, acuminate; lateral sepals 8.3 × 2.3 mm, semi-ovate-lanceolate, oblique, with the upper margin nearly straight, dorsally carinate towards the apex, the keel minutely serrate towards the apex. Petals 6–7 × 0.7 mm, partly spreading, slightly curved, linear-oblong, acute, 1-veined, dorsal surface slightly pustulate, margin slightly undulate. Lip 5.5 × 6.0 mm, united to the column, entire, widely ovate-acuminate, the sides rounded, base truncate, apex acuminate, it can be spread without tearing, longitudinally in-rolled in natural position, embracing the apex of the column covering it; ecallose, without keels, glabrous. Column 4 mm long, straight, thick, with a rounded wing at each side at the apex. Clinandrium-hood reduced, entire. Anther ovoid, fleshy, 4-celled. Pollinia 4, obovate, laterally compressed, the inner side of each pair flat, sub-equal; caudicles granulose, as long as the pollinia; viscidium semiliquid. Nectary without penetrating behind the perianth. Rostellum apical, slit. Capsule ellipsoid, perianth persistent; pedicle 2 mm long, body 12 × 8 mm, apical neck 2 mm.

Etymology: The name honors botanist Miguel Chocce Peña (1977–2017), for his contributions to the knowledge of the orchid flora of Peru. He described 12 new orchid species and co-authored several papers with the authors. Miguel, also participated in the creation of five private conservation areas in Amazonas, all with a high diversity of orchids.

Distribution, habitat and ecology: Epidendrum choccei at present is only known from of the type locality in the north-eastern Peru, where it grows both in elfin forest and Andean tepui vegetation ( Neill et al. 2014) from 2850 to 3450 m elevation. Several fertile and sterile individuals were observed in shrub patches growing as terrestrial and occasionally as epiphytes. Flowering throughout the year.

Comments: Epidendrum choccei is very similar to E. leptanthum Hágsater (2018b : pl. 1677) in terms of the overall appearance of the habit, stems and inflorescence, but can be distinguished by more number leaves on the stem 17–19 (vs 9), shorter leaves 3.4 cm long (vs to 8 cm long) and, pink flowers (vs cretaceous, green flowers), ovate lanceolate sepals (vs ovate-oblong), and lip widely ovate, apex acuminate, ecallose (vs lip cordiform, apex rounded, callose). Also, E. choccei is similar to the holotype of E. stenophyton Schltr (1921:93) in decumbent habit, stems scarcely branching and lineal petals, but can be distinguished by shorter leaves 27–34 mm long (vs 30–50 mm long), longest inflorescence up to 10 cm long (vs 3 cm long), narrowly lanceolate elliptic dorsal sepal (vs oblong) and ovate-acuminate, ecallose lip (rhombic elliptic, callose lip). E. choccei also resembles E. rhombochilum L.O. Williams (1940: 11) in its branched stems, racemose, arching inflorescence and size sepals and petals but can be distinguished by its smaller leaves, 27–34 × 3 mm (vs 22–41 × 3.6–5.1 mm), greater number flowers 19 flowers (vs 3–4) and ovate, ecallose and glabrous lip (vs transversely rhombic, bicallose and pubescent lip). E. chinchaoënse Hágsater, D. Trujillo et E.Santiago ( Hágsater & Sánchez 2009: pl. 1220) also has racemose, arching-nutant inflorescence and lip embracing la column with apex acuminate, ecallose, but differs from E. choccei in its shorter inflorescence 2.7 cm (vs 10 cm) and trullate lip (vs ovate acuminate). In addition, all species grow in high-elevation habitats above 2800 m. E. choccei and E. chinchaoënse are endemic from Peru, the first is only know from an Andean tepui and the second grows in an elfin forest. E. leptanthum is endemic from Ecuadorian paramo and E. rhombochilum has wide distribution from Venezuela to north Peru growing in cloud forest, paramos and grassland. In relation to E. stenophyton we only have the information from the holotype voucher, which indicates the specie is distributed in the shrubland of northern Peru.

OTHER SPECIMENS: PERU. Dept. San Martín. Prov. Rioja. Distrito Pardo Miguel Naranjos, Bosque de Protección Alto Mayo: Andean tepui with sedimentary rock and shrub patches, 3297 m, 01 July 2016, M. Acuña et al. 1402 ( MOL) ; Andean tepui with sedimentary rock and shrub patches, 3214 m, 09 April 2016, M. Acuña et al. 1491 ( USM) .

Figures

FIGURE 1. Plate of Epidendrum choccei. A. Habit. B. Inflorescence. C. Flower, lateral view. D. Flower, longitudinal section. E. Column, lateral view. F. Column, frontal view. G. Dissected perianth. H. Anther. I. Pollinia (from holotype, Acuña 1448). Photographs by José Edquén.

FIGURE 2. Epidendrum choccei. A. Plant in its natural habitat. B. Flowers. C. Inflorescence. D. Fruits (from holotype, Acuña 1448). Photographs by José Edquén.