Epidendrum laciniatum Zambrano & Hágsater, 2021

Romero, Bosco Javier Zambrano, Hágsater, Eric & Solano, Rodolfo, 2021, Miscellaneous of new species in Epidendrum (Orchidaceae) from southwestern Ecuador, Phytotaxa 511 (2), pp. 111-114 : 111-114

Epidendrum laciniatum Zambrano & Hágsater , sp. nov. Figs. 8–10

Species haec Epidendrum ptochicum Hágsater (2006: pl. 877) similis sed sepalo dorsali lanceolato-elliptico, petalis obliquo-oblanceolatis, labelo 5-tuberculato differt.

Type:— ECUADOR. El Oro: Cantón Piñas, Moromoro , sector Quebrada Oscura , 900 m, 31 August 2007, Zambrano B . 217 (holotype, QCNE; isotype, QCNE) .

Epiphytic or terrestrial herb, erect, sympodial, caespitose, up to 150 cm tall including the inflorescence. Roots 1.5–2.0 mm in diameter, from the base of the stems, fleshy, flexuous, white. Stems 20–120 × 0.4–0.6 cm, cane-like, terete, erect, the basal half covered by 7–13 tubular, imbricated, persistent, chartaceous, gray-brown non-foliar sheaths. Leaves 8–11 × 2–3 cm, 6–12 distributed along the apical half of the stem, fleshy, coriaceous, distichous, oblong-lanceolate, obtuse, oblique to slightly bilobed at the apex, channeled at the base; sheaths 2.5–4.0 × 0.5–0.6 cm, longitudinally striated, tubular, persistent, chartaceous, green, purple on underside and margins. Inflorescence up to 80 cm long, apical, erect, a multi-flowered raceme; peduncle 15–70 × 0.2 cm, terete, covered by chartaceous bracts 20–25 × 3–4 mm, conduplicate, persistent; rachis 2–6 × 0.2 cm, terete; floral bracts 2–7 × 1–2 mm, acuminate, persistent, scarious, embracing. Flowers numerous, 5 open at one time, with floral buds in various stages of development, extended, non-resupinate, the sepals, petals and lip orange turning red-orange when old, the callus yellow, column light purple suffused with orange, the anther green-brown. Sepals slightly revolute on the apical half, margin entire; dorsal sepal 10.0–11.5 × 3.8–4.3 mm, lanceolate-elliptic, acute, shortly apiculate, 5–7-veined, with the lateral veins branched, slightly reticulate; lateral sepals 10–11 × 4.0– 4.5 mm, obliquely oblanceolate, obtuse, shortly apiculate, carinate dorsally, 7-veined, with the lateral veins branched, slightly reticulate. Petals 10.0–11.3 × 2.8–3.3 mm, slightly revolute at apex, obliquely oblanceolate, acute to obtuse, margin somewhat undulate, 5-veined, with the lateral veins branched. Lip 10–11 × 11–13 mm, deeply 3-lobed, fused to the column, cordate at the base; callus massive, formed by 5 unequal tubercles, acute, the mid protuberance obovoid, apically triangular, not reaching the sinus of the apical lobe, the lateral protuberances shorter, with another pair of basal, ovoid-triangular, acute, divergent structures, all forming a groove on the middle at the base; lateral lobes 4.5–5.5 × 5.5–6.0 mm, trapezoid, distally deeply laciniate; mid-lobe 5.0–7.0 × 9.0–10.0 mm, flabellate with a narrow isthmus in the basal half, apical half bilobed, the lobes divergent, oblong, distally deeply laciniate, with a mucro in the apical sinus. Column 6.0–6.5 × 1.3–1.5 mm, short, slightly arched near the base, terete, with a digitiform, truncate lateral wings extending on each side, slightly divergent; clinandrium-hood short, covering only the base of the anther, margin minutely undulate, the lateral sides minutely dentate marginally; stigma ventral, concave, covered by a viscous substance; rostellum apical, laminar, slit; nectary deep, penetrating about half the ovary, minutely papillose. Ovary 25.0–30.0 × 1.3–1.5 mm, arching, terete, longitudinally sulcate. Anther 1.5 × 0.9 mm, dorsal, ovate, glandular-papillose; pollinarium 1 mm long, formed by 4 pollinia, yellow, oblanceolate, sub-equal, laterally compressed, caudicles imbricated, granulose. Capsule not seen.

Distribution and habitat: —The new species is only known from Piñas and Atahualpa in El Oro province ( Fig. 10 ). Epidendrum laciniatum grows as an epiphyte on shrub branches of Miconia species , or rarely in organic matter and moss, at 650–1300 m in elevation.

Phenology: —In cultivation E. laciniatum flowered between May and August.

Etymology: —The specific epithet derives from the Latin laciniatus “slashed into narrow divisions with taperpointed incisions”, in reference to the distal margins of the lip.

Additional material examined:— ECUADOR. El Oro: Cantón Piñas: Piñas to Machala , km 10, 1000 m, 19 July 1979, Dodson et al. 8455 ( SEL). Cantón Piñas, sector Monos, 1100 m, 11 October 2007, Zambrano B . 299 ( QCNE). Cantón Piñas , sector La Garganta, 1100 m, 11 October 2007, Zambrano B . 301 ( QCNE). Cantón Piñas, sector Libertad , 1000 m, 12 November 2007, Zambrano B . 390 ( QCNE). Cantón Piñas, parroquia Moromoro, sector Quebrada Oscura , 1000 m, 06 December 2008, Zambrano B . 642 ( QCNE). Cantón Piñas, parroquia Moromoro , sector El Placer-Palosolo, 981 m, 30 June 2014, Zambrano B . 1530 ( QCNE). Cantón Piñas, parroquia Moromoro, camino antiguo Palosolo , 1241 m, 30 June 2014, Zambrano B . 1560 ( QCNE). Cantón Atahualpa, sector Cerro Azul , 1013 m, 19 July 2019, Zambrano B . 2402 ( QCNE). Cantón Atahualpa , Hcda. Daucay, 650 m, 14 October 1993, X. Cornejo 515 ( GUAY, QCNE) .

Comments: —The new species belongs to the Schistochilum group, and is distinguished by its oblong-lanceolate leaves, the light orange, non-resupinate flowers turning red-orange with age, the obliquely oblanceolate petals, and the lip with 5-tubercles, and the distal margins of the lateral and mid-lobe strongly laciniate. The most similar species is E. ptochicum , which is known to occur from Colombia to Peru. It differs from E. laciniatum in the deep orange to red flowers (vs. light orange, turning red-orange with age), the shorter dorsal sepal (8–9 mm vs. 10.0– 11.5 mm long), the obovate petals (vs. obliquely oblanceolate), the smaller lip (7.6 × 9.6 mm vs. 10–11 × 11–12 mm), bearing a callus with 7-tubercles (vs. 5-tubercles), the mid-lobe scarcely laciniate not bilobed at the apex (vs. strongly laciniate, bilobed), and column with an entire clinandrium-hood (vs. minutely undulate-dentate). The Ecuadorian Epidendrum portokalium Hágsater & Dodson (2004: pl. 778) is similar in color but it differs the lanceolate leaves (vs. oblonglanceolate), orange-red flowers (vs. light orange, turning red-orange with age), the elliptic dorsal sepal (vs. lanceolateelliptic), the 3-veined petals (vs. 5-veined), lip with a callus formed by 7-tubercles (vs. 5-tubercles), the lateral and mid lobe fimbriate (vs. strongly laciniate), and the shorter column (5.0 mm vs. 6.5 mm).

Figures

FIGURE 8. Epidendrum laciniatum Zambrano & Hágsater. A. Habit. B. Flower, frontal view. C. Perianth dissection. D. Ovary and column, lateral view. E. Detail of the column, lateral and ventral view. Drawn by B.J. Zambrano based on the plant that served as type.

FIGURE 9. Epidendrum laciniatum Zambrano & Hágsater. A. Habit. B. Flower, frontal view. C. Perianth dissection. D. Ovary and column, lateral view. E. Detail of the column, lateral and ventral view. F. Detail of the callus, frontal and 3/4 view. G. Anther cap and pollinarium. Plate by B.J. Zambrano based on the plant that served as type.

FIGURE 10. Known locality of Epidendrum laciniatum in southwestern Ecuador. Map by B.J. Zambrano.