Vanilla andina Damián & H. Garzón, 2022

Damián, Alexander, Garzón, Henry X., Baquero, Luis, Jiménez, Marco M., Vélez-Abarca, Leisberth, Iturralde, Gabriel A., Mitidieri, Nicole, Olortegui, Sergio & Cameron, Kenneth M., 2022, Vanilla andina (Vanilloideae, Orchidaceae), a new species of the membranaceousleaved group from Peru and Ecuador, Phytotaxa 552 (1), pp. 63-72 : 64-70

Vanilla andina Damián & H. Garzón , sp. nov. ( Figures 1–4 ).

Type:— PERU. San Martin: Lamas, Pinto recodo, Centro Poblado Jesus del Monte , 6 3’ 43.6” S 76 48’ 59.7” W, 1248 m, August 2019, S. Olortegui & A. Damian 908 (holotype: USM!) .

The overall flower color and labellum of Vanilla andina are reminiscent of Vanilla armoriquensis . However, the new species may be easily distinguished by the slightly smaller flower with sepals and petals 4–6.1 × 0.9–1.7 cm (vs. 5–5.5 × 1–1.3 cm), oblong to sub-orbicular lip shape (vs. sub-rectangular), longitudinal narrow keels that start at the base of the labellum and extend fully to the middle of the lateral lobes (vs. 1/4) and a broadly obtuse to emarginate crisped labellum mid lobe (vs. triangular acuminate, with involute margins).

Description:— Hemiepiphytic herb, leafy, that branches out as it grows up to 12 m long. Stems flexuose, terete, dark green, usually verruculose, 0.40–0.77 cm wide; internodes 3–16 cm long. Aerial roots, terete, whitish, 1.5–9 × 0.2–0.36 cm. Leaves green to dark green, sessile, shiny adaxially and abaxially; blade elliptic, lanceolate when young and orbicular close to the flowering buds, base attenuate to rounded, apex acuminate to caudate, membranaceous, turning dark brown when senescent, becoming blackish after herborization, margins wavy when fresh, mid-vein sulcate, veins conspicuously reticulate, 9.5–18 × 6.5–7 cm. Inflorescence axillary, racemose, rarely paniculate, successively 3–5 flowered; peduncle 0.6–2.8 cm long, rachis 7–19 cm long; bracts at the base of the inflorescence green, generally small secondary branches, 2–2.5 × 1–1.5 cm. Floral bracts foliaceous, reticulate, 5.5–8 × 3–5 cm. Flowers resupinate, pendular, sepals and petals pale green or dark green, lip white, salmon-colored adaxially at the base, fragrant. Ovary pedicellate, terete, sinuous, curved, something sigmoid, 3–5 × 0.4 cm including the pedicel. Dorsal sepal lanceolate to narrowly elliptic; margins undulate, repand, sinuate and curled; base truncate and cuneate, apex acute recurved, revolute, apically twisted, 8–9–veined, 4.4–6.1 × 1.3–1.5 cm. Lateral sepals similar to the dorsal sepal in shape, 4–5.9 × 1–1.7 cm. Petals lanceolate to narrowly lanceolate; margins undulate, repand-crisped, recurved at apex, adaxial surface with a central vein canaliculate along, abaxially sulcate along the midvein, 10–12-veined, 4–5.9 × 0.9–1.2 cm. Labellum white suffused with salmon markings towards the base and at the midline, free, slightly arcuate, ca. 2.6–3 × 3.7–4.1 cm, three-lobed when extended and forming a tube in its natural position, the margins gradually change from entire to sinuate and crispate at the apex, narrowly channeled abaxially, truncate at the base where attached to the column, with several longitudinal and tall narrow keels conspicuously antrorse-verrucose that extends to the ½ of the lateral lobes; lateral lobes shoulder-shaped, broad, forming a oblong–suborbicular blade with erose to undulate margins; the disc with a two thick, high, ribbed, sigmoid keels, at both sides of the midline with low internal carinae extending to the apex of the midlobe, which collapse towards a central, thick, sub-rectangular, rugose-striated 8–keeled callus that arise from near the middle of the lip and end into a sharp, sub-obtuse point, 3 × 3 cm long; midlobe white overall, greenish close to the apex and in the middle portion, broadly obtuse to emarginate, middle portion incurved with margins strongly crispate, 1.2 × 1.5 cm. Column white to yellowish-greenish, ca. 1.6–2.0 × 0.17–0.20 cm, erect, with 4–8 bullate-rugose, orange longitudinal keels, which extend close to the middle at the base of the ventral surface, glabrous, the apex winged with a two-horned clinandrium. Stigma trilobed, the lateral lobes subquadrate, ca. 0.1 × 0.2 cm, rostellum ca. 0.3 × 0.25 cm, convex, quadrate, the superior margins denticulate and basal ones revolute. Anther ca. 0.35 × 0.2 cm, saddle-shaped, with two horn-shaped projections and with pollen grains not forming a pollinarium but two granular masses. Fruit green to dark green, ca. 18–21 × 0.8–1.3 cm, pendular, cylindrical, fleshy, tricarpellate, unilocular.

Distribution and ecology:—So far known only from the type locality in the San Martin department of Peru and the Morona-Santiago province of Ecuador where the species inhabits the pre-montane forest of the eastern slopes of the Andes at ranges of 1100–1250 m in elevation. The Peruvian plant has been seen growing in a coffee plantation surrounded by secondary forest dominated by Calophyllum brasiliense Cambess. (1828: 320) and Inga sp. , whereas the Ecuadorian specimen has been found climbing trees of Piptocoma discolor ( Kunth 1818: 35–36) Pruski (1996: 97) (Asteraceae) in a forest also composed by Tachigali sp. , Zygia longifolia ( Willdenow 1806: 1010) Britton & Rose (1928: 40) (Fabaceae) and Wettinia maynensis Spruce (1859: 194) (Arecaceae) . The distance between these two known populations is 400 km, which is not surprising for the genus; occurrence in nearby areas is highly probable. Flowers and fruits have been seen at the same time (July-September and November-December) in both populations studied. Flowers are slightly aromatic, but no pollinators have been observed.

Etymology:—The specific epithet of the new taxon is a reference to the Andean mountain range, where the species is found.

Additional specimens examined (paratype):— ECUADOR. Morona Santiago: Near San Juan Bosco , 3º 07’ 39.7” S 78 32’ 33.1” W, 1125 m, 23 August 2021, M. Jiménez & H. Garzón 1274 (QCNE!; HA!; HUTPL!) .

Taxonomic Discussion:— Vanilla andina is almost certainly closely related to a small group of morphologically similar species that includes V. amoriquensis , Vanilla costaricensis Soto Arenas (2010: 297) and V. oroana , all featuring foliaceous bracts, a white colored lip with salmon-pink markings, conspicuously tall parallel callus close to or below the middle, and a horned anther. Species members of this group can be easily distinguished mainly by its different lip shape, and midlobe morphology (see Table 1 , Figure 4 ). Other membranaceous species differs from V. andina and allies by having: a pair of tall broad confluent keels in V. sarapiquensis Soto Arenas (2010: 342) ; flat disc with truncate mid lobe in V. methonica Reichenbach & Warszewicz (1854: 97) ; fleshy disc with 3 thickened keels in V. mexicana ; a massive cushion callus in V. inodora Schiede (1829: 574) ; broadly hexagonal lip in V. guianensis Splitg. (1841: 279) ; subtrilobed truncate lip in V. arcuata Pansarin & M.R. Miranda (2016: 85) ; laminar apical crests of V. edwallii Hoehne (1950: 61) and V. parvifolia Barb. Rodr (1881: 271) ; strongly papillate disc in V. angustipetala Schltr. (1922: 19) ; and terrestrial habit in V. dietschiana Edwall (1903: 192) . The rest of membranaceus names [ V. acuta Rolfe (1896: 453) , V. bertoniensis Bertoni (1910: 10) , V. bradei Schltr. ex Mansf. (1928: 243) , V. organensis Rolfe (1896: 452) , V. verrucosa Hauman (1917: 365) ] are of dubious definition and might represent synonyms of previous names according to Soto Arenas & Cribb (2010).

Known populations of Vanilla andina shows some morphological variation, the most conspicuous being the shape of the lip midlobe ( Figures 2 , 3 ) which in the Peruvian material is broadly obtuse vs. emarginate in the Ecuadorian population. This sort of variation is expected in such a wide range of distribution (> 400 km distance between them) and is coherent with other members of the genus such as V. mexicana , V. pompona Schiede (1829: 573) ( Karremans et al. 2020) and V. oroana (protologue vs. Figure 4A ).

Members of the subgenus Vanilla are poorly understood, and details about their pollination biology and evolutionary relationships have not been fully explored. Morphologically they were merged by Soto Arenas & Cribb (2010) into to informal groups, the V. mexicana and V. parvifolia groups, but the limit of their artificial grouping is controversial. For example, V. costaricensis was included in the V. mexicana group due to the lack of a basal triangular keel on the abaxial surface of the column, but at least V. armoriquensis which is alike to V. costaricensis , has this keel. The same inconsistency is seen with the non-undulate or involute petals used to distinguish the V. parvifolia group, but which are present in V. angustipetala and V. edwallii that are proposed to belong to that group. A more thorough systematic and evolutionary assessment of subgenus Vanilla is needed to clarify their taxonomy, but also to bring to light a better understanding of how this ancient Vanilla lineage evolved and maintains its place across the Neotropics.

Figures

FIGURE 1. Lankester Composite Dissection Plate (LCDP) of Vanilla andina. A. Habit. B. Flower. C. Dissected perianth. D. Lip and column (left) and in longitudinal section (right). E. Column, ventral (left), lateral (center) and dorsal (right) view. F. Anther cap in dorsal. (above left), ventral (above right), lateral (below, left) view, with pollinarium (below right). Photographs by Henry X. Garzón based on M. Jiménez & H. Garzón 1274.

FIGURE 2. Line drawing of Vanilla andina based on the Peruvian holotype. A. Habit, B. Inflorescence, C. Flower in lateral view, D. Dissected perianth. E. Lip and column, lateral view. F. Column, ventral (right) and lateral view (left). G. Anther cap in dorsal (left) and ventral (right) view. Drawing by N. Mitidieri.

FIGURE 3. Line drawing of Vanilla andina based on the Ecuadorian specimen. A. Habit, B. Flower, C. Dissected perianth. D. Lip and column, lateral view. E. Column, ventral and lateral view. Drawing by Leisberth Velez-Abarca.

FIGURE 4. Lip distended comparison of A. Vanilla oroana, B. V. armoriquensis, C. V. andina, D. V. costaricensis. Photographs by (A) F. Tobar, (B) A. Damian, (C) H. Garzón, (D) A. Karremans. Scale bar: 2 cm