Epidendrum quimiense N. Lapo-Gonzalez, M.M.Jiménez & Vélez-Abarca, 2024

Lapo-Gonzalez, Nadia, Hágsater, Eric, Vélez-Abarca, Leisberth, Mendoza Uyaguari, Johny J., Kuethe, J. R. & Jiménez, Marco M., 2024, A new species of Epidendrum (Laeliinae: Orchidaceae) from the province of Zamora Chinchipe in Ecuador, Phytotaxa 650 (2), pp. 185-193 : 186-191

Epidendrum quimiense N. Lapo-Gonzalez, M.M.Jiménez & Vélez-Abarca , sp. nov. ( Figures 1–2 ).

Type:— ECUADOR. Zamora Chinchipe: Valle del Quimi, Cordillera del Cóndor , 1157 m, 17 Ene 2023, N. Lapo-Gonzalez 75 (holotype: LOJA 42885 !).

Similar to Epidendrum marci-jimeneziorum Hágsater & Jiménez in Hágsater & Santiago (2018: 1681) from which it differs by having the leaves elliptic-lanceolate (vs. narrowly elliptic), the inflorescence 4.0–8.0 cm long (vs. 3 cm long), the flowers 1–7-successive (vs. 3-successive), the ovary 22.0–25.0 mm long (vs. 18 mm long), the dorsal sepal 17.0 × 6.0 mm (vs. 8.5 × 4 mm); the lateral sepals 18.0 × 6.0 mm, oblanceolate (vs. 9.0 × 4.5 mm, obliquely obovate), and the lip 13.0–15.0 × 14.0–18.0 mm, reniform, bilobed (vs. 7.0 × 12.0 mm, sub-reniform, slightly 3–lobed).

Description:—Epiphytic, sympodial, scandent. Herb up to 60 cm tall, the new stems arising from a sub-apical internode of the previous stem. Roots 3–4 mm in diameter, basal from primary stem, fleshy, green. Stems 6.0–18.3 × 0.3–0.4 cm, terete, thin, straight, produced from the middle of the previous stem, covered by 2 foliaceous, striate, papery sheaths, 0.4–0.6 × 1.0– 1.3 cm. Leaves 2–4 per stem, aggregate at the apical third of the stem, blade elliptic-lanceolate, acute, margin entire, 3.0–9.0 × 0.9–2.5 cm. Spathe lacking. Inflorescence 4.0–8.0 cm long, apical, racemose, successively flowered, arched, rachis slightly flexuous, 2.0– 3.2 cm long; pedicel 1.0– 1.8 cm long; peduncle 2.0–3.0 cm long, laterally compressed. Floral bracts 4.0–1.0 × 4.0–5.0 mm; triangular, acuminate, embracing. Flowers 1–7, successive, several open at once, yellowish green, column slightly suffused with purple at apex, lip paler towards margins and calli; fragrance unknown. Ovary 22.0–25.0 × 4.0 mm, slightly arcuate, semi-terete, slightly furrowed, ventrally inflated along apical half. Sepals 15.0–18.0 × 5.0–6.0 mm, spreading, oblanceolate, acute, slightly reflexed, margins entire, longitudinally convex; dorsal sepal 17.0 × 6.0 mm, spreading, oblanceolate, acute, margins entire, 4–veined; lateral sepals 18.0 × 6.0 mm, somewhat falcate, spreading, oblanceolate, acute, margins entire, 6–veined. Petals 15.0–18.0 × 4.0–5.0 mm, oblanceolate, apical half somewhat rhombic, apex acute, 3–veined, slightly revolute to base, margins entire. Lip 13.0–15.0 × 14.0–18.0 mm, united to column, bilobed, reniform, fleshy, 12–veined, laterally revolute, lip apron-shaped in natural position, abaxial surface rugose, base cordate, apical margin slightly undulate, emarginate callus unornamented; lobes semi-orbicular 11.0 × 14.0 cm, margins entire, base with 2 fleshy, globose, separate calli. Column 10.0–11.0 mm long, short, straight, fleshy, thickened at apex, constricted at base. Anther 2.0 mm wide, sub-spherical-reniform, lime-green. Pollinia 4, ovate, slightly laterally compressed, pale yellow, caudicles granulose and soft. Rostellum apical, slit; viscarium semi-liquid. Cuniculus deep, penetrating half pedicellate ovary, narrow. Capsule not seen.

Distribution and ecology:— Epidendrum quimiense is known from three locations in the province of Zamora Chinchipe, in southeastern Ecuador ( Figure 3 ). Two of them belong to the Cordillera del Cóndor, in the premontane forests of sandstone plateaus ( Neill 2005), at an altitudinal range that goes from 800 to 1200 m. The new species grows epiphytically at about 3 m above the ground, in aggregates of few individuals separated by several dozens of meters. Epidendrum quimiense is associated with the remaining vegetation close to rivers, the ecotone areas between forests and pastures, and remnant trees in pastures. It shares the habitat with other orchid species such as Masdevallia guerrieroi Luer & Andreetta (1978: 373) , Stelis nexipous Garay (1958: 154) and Telipogon leisberthvelezii Iturralde, Jiménez & Garzón (2024: 98) .

The third locality is on the edge of a river near the town of Zamora. Plants grow between the middle and lower strata on trees of Perrottetia sp. ( Dipentodontaceae ), in lower montane forests around 1000 m in altitude on the Amazonian slope of the Andes ( Figure 4 ). In nature, E. quimiense blooms from January to November.

Etymology:—In reference to El Quimi Biological Reserve in the province of Morona-Santiago, southeast Ecuador. The new species has been found near the reserve.

Additional specimens examined (paratypes):— ECUADOR. Zamora-Chinchipe: El Pangui , Cordillera del Cóndor , 1258 m, 27 Sep 2022, L. Vélez-Abarca 89 ( ECUAMZ!) ; Cerca de Zamora , 1014 m, 14 May 2023, M.M. Jiménez 1772 ( HUTPL 15002!) .

Conservation status:—To date, Epidendrum quimiense is known only from three separate populations, where each population exhibits low abundance containing 1–3 plants per phorophyte, making it essentially a narrow endemic to Ecuador. These populations were seen across an area of occupancy (AOO) of 16 km 2, with an extent of occurrence (EOO) of 68 km 2. Within this distribution, E. quimiense was seen in disturbed forests (activities including mining, livestock breeding, and deforestation), hence the long-term conservation of this species could not be assured. For the reasons outlined above, the authors class E. quimiense as EN (Endangered) in accordance with the IUCN (2017) categories B2acC2aiibD1.

Taxonomic discussion:— Epidendrum quimiense belongs to the informal taxonomic Incomptum group which is characterized by the successive lateral growths produced from the middle of the previous growth, the few leaves aggregated towards the apex of stems, a short apical inflorescence with fleshy green to violet-green flowers with short ovaries, and the lip entire, bilobed. The new species is recognized by the acute, elliptic-lanceolate leaves, the ovary ventrally inflated along the apical half, the greenish flowers with the dorsal sepal about 15–18 mm long, acute, slightly reflexed, oblanceolate, the petals 15–18 × 4–5 mm, acute, 3–veined, oblanceolate with the apical half subrhombic, the lip emarginate, bilobed, reniform with the lobes semi-orbicular, strongly revolute, apron-shaped in natural position, the margins entire, somewhat undulate at the apex and the column 10–11 mm long, straight, thick at the apex. It is somewhat similar to E. marci-jimeneziorum which has plants to 26 cm tall (vs. 60 cm tall); inflorescence of 3 cm long (vs. 4–8 cm long); flowers 3 (vs. flowers 1–7); petals 8.0 × 2.5 mm, inflexed (vs. 15–18 × 4–5 mm, slightly revolute to base); lip 7 × 12 mm, sub-reniform (vs. 13–15 × 14–18 mm, bilobed, reniform); column 6.0– 6.5 mm long (vs. 10–11 mm long); sepals partly spreading (vs. spreading). Epidendrum chisquillense Hágsater, Edquén & Cisneros (in Hágsater & Santiago 2020: pl. 1806) has free, partly spreading petals, 1–veined, the sepals are 3–veined, revolute, somewhat falcate, the lip obreniform,base truncate, with three very short parallel low ribs and the anther is cordiformsubspherical. Epidendrum ulcumanoae Hágsater, Gerlach & Valenzuela (in Hágsater & Santiago 2020: pl. 1844) has sepals and petals olive green to yellow-tinged somewhat brown, the ovary long, slightly ventrally inflated, apiculate, the lip obreniform, widest at the middle, the lateral lobes semi-orbicular, with a slightly receded mid-lobe ( Figure 5 ).

Furthermore, the four species are reported in the eastern slopes of the Andes, Epidendrum quimiense grows at lower elevations from 1000 to 1300 m, restricted to the warmer premontane forests near Zamora and the Cordillera del Cóndor in Zamora Chinchipe Province ( Figure 4 ), while according to Hágsater & Santiago (2019), E. marci-jimeneziorum which inhabits towards the north of the new species, grows at higher altitudes from 1050 to 1671 m in lower montane and premontane forests of the Morona Santiago and Napo provinces. To the south, the Peruvian E. chisquillense and E. ulcumanoae both grow at higher elevations between 2200 to 3400 in montane and high Andean forests of the departments of Amazonas (northeastern) and Pasco (central), respectively.

Figures

FIGURE 1. Epidendrum quimiense N. Lapo-Gonzalez, M.M.Jiménez & Vélez-Abarca. A. Habit. B. Flower. C. Anther and pollinia. D. Column and ovary, lateral and longitudinal cut view. E. Detail of the column, ventral view. F. Column with lip, lateral view. G. Lip, adaxial and abaxial view. H. Dissected perianth. Illustration by Johny J. Mendoza Uyaguari, based on the holotype.

FIGURE 2. Lankester Composite Dissection Plate (LCDP) of Epidendrum quimiense N. Lapo-Gonzalez, M.M.Jiménez & Vélez-Abarca. A. Habit. B. Flower. B1. Anther and pollinia. C. Dissected perianth. D. Lip, adaxial and abaxial view. D1. Detail of the lip, abaxial view. E. Column with lip, lateral view. F. Column and ovary, lateral and longitudinal cut view. F1. Detail of the column, ventral view. Elaborated by N. Lapo-Gonzalez, from photos of the holotype by M.M. Jiménez.

FIGURE 3. Distribution map of Epidendrum quimiense. Elaborated by N. Lapo-Gonzalez.

FIGURE 4. Epidendrum quimiense in situ. A. Plant growing epiphytically on tree trunk. B. Flower (front view). Elaborated by N. Lapo- Gonzalez (Photographed in situ by M.M. Jiménez.).

FIGURE 5. Floral comparison of flowers (A) and lips (B) of morphologically similar species. A1. Epidendrum marci-jimeneziorum. A2. Epidendrum quimiense. A3. Epidendrum chisquillense. A4. Epidendrum ulcumanoae. B1. Epidendrum marci-jimeneziorum. B2. Epidendrum quimiense. B3. Epidendrum chisquillense. B4. Epidendrum ulcumanoae. Elaborated by N. Lapo-Gonzalez from photos of the Epidendrum marci-jimeneziorum by R. Jiménez, Epidendrum quimiense by M.M. Jiménez, Epidendrum chisquillense by J.D. Edquén and Epidendrum ulcumanoae by E. de la Cadena.