Cyclopogon soniae-juaniorum Zambrano, 2018

Romero, Bosco Javier Zambrano & Solano, Rodolfo, 2018, A new species of Cyclopogon (Orchidaceae: Spiranthinae) from southwestern Ecuador: Cyclopogon soniae-juaniorum, Phytotaxa 376 (5), pp. 201-206 : 202-206

Cyclopogon soniae-juaniorum Zambrano , sp. nov. ( Figs. 1–3 )

Type:— ECUADOR. El Oro: Cantón Piñas, sector La Garganta, 1100 m, 11 October 2007, Zambrano 272 (holotype QCNE; isotype QCNE, in spirit) .

The new species is similar to Cyclopogon hennisianus , from which it is distinguished by being epiphytic and having an oblong-lanceolate dorsal sepal, linear-oblong petals, an unguiculate lip with tiny, intramarginal, thickened, translucent, rounded calli, an oblong-pandurate hypochile and an oblong-ovate epichile.

Epiphytic, acaulescent herbs, 20–60 cm tall including inflorescence. Roots fascicled, pilose, 20–40 mm long, 5.0–7.0 mm in diameter. Leaves erect, 1–8, arranged in a basal rosette, petiolate, subtended at their base by 2–3 translucent, funnel-like, imbricating, scarious sheaths, 8.0–40.0 × 4.0–8.0 mm when spread out; petiole channeled, 30– 90 mm long; blade dull green (brown when dried), elliptic-lanceolate to obliquely elliptic, acute, conduplicate toward the base, 40–130 × 10–40 mm. Inflorescence up to 58 cm long with up to 100 flowers, 5–30 open simultaneously, subtended at base by 3–4 funnel-like, imbricating, acute, scarious, translucent sheaths, 15.0–70.0 × 4.0–12.0 mm when spread out; peduncle green, 2.0–5.0 mm in diameter, glabrous on the proximal 2/3, pilose above, partially enclosed by 4–7 loose, lanceolate, long-acuminate, pale green, translucent bracts 30.0–40.0 × 1.0–7.0 mm when spread out. Floral bracts pale green, translucent, conspicuously longer than the ovaries, linear-lanceolate, acuminate, concave, 10.0–20.0 × 2.0–4.0 mm when spread out. Flowers resupinate, ascending, tubular, sepals green, petals and labellum green, white at their apices with a green stripe above the middle. Ovary sessile, arcuate, fusiform, terete, sparsely pilose, 5.0–11.0 mm long, 1.5–2.5 mm in diameter. Sepals sparsely pilose and sometimes white-spotted on the abaxial surface, membranous, translucent, 1-nerved, dorsal sepal concave, oblong-lanceolate, acute, slightly recurved at the apex, 6.0–7.0 × 1.0– 1.5 mm; lateral sepals concave, obliquely oblong-lanceolate, obtuse, 7.0–8.0 × 0.9–1.2 mm. Petals translucent, linear-oblong, obtuse, slightly wider toward the apex, concave, 1-nerved, 5.0–6.5 × 0.8–1.0 mm. Lip channeled in natural position, shortly unguiculate, divided into a hypochile and epichile, attenuate at base, with a tiny, intramarginal, thickened, translucent, rounded calli on each side of the base, the hypochile conduplicate-channeled in natural position, oblong-pandurate when spread out, strongly recurved apically, 3-nerved, ca. 4.0–4.5 × 2.0– 2.1 mm, the epichile more or less oblong-ovate, crenulate, slightly trilobed, minutely papillose apically, ca. 2.5–3.0 × 2.0 mm. Column slightly recurved, claviform, shortly pubescent and channeled on ventral surface, 4.0– 4.3 mm long, with a column foot.Anther dorsal, elliptic-ovate, concave, bilocular, 1.3–1.5 × 0.7–0.8 mm, hinged by a filament. Pollinarium 1.3 mm long, formed by 2 claviform, longitudinally cleft, whitish, granular pollinia, gradually attenuated towards the apex, attached to a wedge-type viscidium. Rostellum linear, laminar, oblong-triangular, 0.9–1.0 mm long, rostellum remnant truncate; stigma ventral, slightly concave, bilobed. Capsule narrowly ellipsoid, with a persistent perianth, 11–14 mm long (14–18 mm including the remnant column), 3.5–4.0 mm in diameter when mature.

Distribution and habitat:— Cyclopogon soniae-juaniorum is only known from southwestern Ecuador, El Oro Province, where there are only three localities reported. This species grows between 785–1200 m elevation in evergreen premontane forest and semi-deciduous forests ( Fig. 3 ). The plant grows as an epiphyte on Yucca species and fallen trees.

Phenology:— In cultivation, flowering July–October.

Etymology:— Named in honour of Sonia Romero, Juan Zambrano and Juan Pablo Zambrano, parents and brother of the first author, who have contributed substantially to our research on Orchidaceae of Ecuador.

Additional specimens examined:— Ecuador. El Oro: Cantón Piñas, sector Piñas Grande, 1200 m, 12 December 2007, Zambrano 510 ( QCNE) ; Cantón Santa Rosa, sector El Guayabo, 785 m, 09 July 2016, Zambrano 1786 ( QCNE) .

Notes:— Cyclopogon soniae-juaniorum is the unique among Cyclopogon species due to its tiny basal calli, but it is similar to species such as C. argyrotaenius , C. ellipticus , C. epiphyticus , C. gracilis and C. hennisianus . The most similar species is the Ecuadorian and Colombian C. hennisianus , but it is different in its terrestrial habit (vs. epiphytic), variegated leaves (vs. dull-green), oblong dorsal sepal (vs. lanceolate), acute lateral sepals (vs. obtuse), shorter and oblong-obovate petals (≤ 5.5 mm vs. 6.5 mm, linear-oblong) and a sagittate-subquadrate lip with small conical calli (vs. oblong-pandurate, with tiny, translucent and rounded) ( Sandt 1928, Garay 1978, Dodson 1993b). Table 1 shows a summary of the morphological characteristics that differentiate the other similar species.

Conservation status:— Cyclopogon soniae-juaniorum occurs in remnant forest disturbed by human activities (La Garganta, Piñas Grande, El Guayabo), where the populations exhibit low densities (1–3 plants per host shrub). Furthermore, they are outside protected areas, so the conservation of this species would depend on ensuring the persistence of its habitat.

Figures

FIGURE 1. Cyclopogon soniae-juaniorum Zambrano.A. Habit.B. Flower, lateral view. C. Floral dissection. D. Ovary and column, lateral view. E. Column, ventral and lateral view. F. Pollinarium from below and above. Drawn by B.J. Zambrano from the holotype.

FIGURE 2. Cyclopogon soniae-juaniorum Zambrano.A. Habit, inflorescence and dried leaf. B. Floral bract and flower in lateral view. C. Segment of inflorescence. D. Floral dissection. E. Ovary, column and lip, lateral view. F. Detail of the column, ventral surface. G. Detail of the rostellum, lateral, dorsal and ventral surface. H. Details of the calli, base and dorsal surface of the lip. I. Anther and pollinarium. J. Capsule with persistent perianth. Plate by B.J. Zambrano based on Zambrano 272, 510 and 1786.

FIGURE 3. Localities for Cyclopogon soniae-juaniorum in southwestern Ecuador. Map by B.J. Zambrano.