Vanilla javieri Barona-Colmenares, 2018

Barona-Colmenares, Andrés A., 2018, Two new records in Orchidaceae (Vanillinae) from southernmost Colombian Amazonia: Vanilla javieri, a new species, and Vanilla appendiculata, Phytotaxa 375 (4), pp. 261-273 : 263-268

Vanilla javieri Barona-Colmenares , sp. nov. ( Figs. 2 , 3 , 5 & Table 1)

Diagnosis: —The new species resembles V. appendiculata ; however, vines seem to be smaller and bear racemes with fewer, completely greenish cream-colored flowers. More importantly, the inner surface of the claw is lanuginose (vs. warty), the lip apex is adorned by fewer and smaller papillae, and the fruits are pendant (vs. erect). Vanilla javieri is easily distinguished by the following combination of characters within the V. planifolia group: small understory hemiepiphyte vine bearing oblong-elliptic and abruptly mucronate coriaceous leaves; terminal inflorescences with a basal, sub-cordate, non-floriferous foliaceous bract; small, greenish cream-colored flowers bearing a column with a glabrous ventral surface; a narrow, acute, strongly reflexed lip apex with two rows of digitiform papillae forming a V-shape along the margins of an inconspicuous cushion-like apical longitudinal crest; and pendant, arcuate, rather stout, obscurely calyculate fruits that are highly aromatic when dehiscing.

Type: — COLOMBIA, Departamento de Amazonas: Leticia, secondary forest on the road from Leticia to Tarapacá, 4° 03’ S, 69° 59’ W, 100 m elev., 19 May 2017, fl. & fr., A.A. Barona-Colmenares & L. Pinedo 4666 (holotype COAH!).

Small, hemiepiphyte understory vine, ca. 1.2 m high. Stems 4–5 mm in diameter, dark green towards the base, fading to bright green towards the apex, cylindrical, smooth, flexuous, sinuous to zigzagging; internodes 30–54 mm long. Leaves 113–148 × 37–49 mm, alternate, oblong-elliptic, fleshy, coriaceous, shiny deep emerald green in color and with a conspicuous canaliculate petiole 3–12 mm long × 3–9 mm wide; blade longer than the internodes and bearing a conspicuous whitish collecting vein along the margins, widest at three quarters from the base and abruptly mucronate near the acute and recurved apex. Inflorescence terminal, racemose, with 6–20 successive flowers, generally one or occasionally two open at once; scape 30–80 mm long, green, erect, slightly sinuous, stouter than stem; floral bracts 4–6 mm long × 4–6 mm wide, small, triangular-ovate, coriaceous, canaliculate, patent, same green as scape with whitish margins; basal floral bracts distichous, up to 4 non-floriferous; the basal bract 9–11 mm long × 6–7 mm wide, foliaceous, green, subcordate with conspicuous longitudinal veins converging at apex; the remaining apical bracts floriferous and arranged spirally. Flowers resupinate, small, 3–5 cm in diameter, with partially spreading segments, completely greenish cream-colored and with a weak citrus odor. Ovary 32–35 mm long × 4–5 mm in diameter, slightly dorsiventrally compressed, white fading to green towards the apex, obscurely calyculate, with the calyculus margin broadly undulate. Sepals free, oblanceolate, narrow, cream-colored, merged at base with column for 9–10 mm, abaxially greenish cream-colored with the apex tinged with green, concave, margin involute, apex acute and with conspicuous crystal druses; dorsal sepal 91 × 12 mm, symmetric, smooth, concave with involute margins and ca. 13 veins; lateral sepals 84.5–86 × 12–13 mm, asymmetric, smooth, concave with involute margins and ca. 14 veins. Petals 86–89 × 11–12 mm, cream-colored, greenish cream-colored abaxially, merged at base with column for ca. 9–10 mm, narrow lanceolate, asymmetric, basally concave and convex towards the apex, with an externally prominent central rib, ca. 13 yellowish cream-colored veins, slightly rounded apex and conspicuous crystal druses. Labellum long unguiculate, inner surface of the claw lanuginose; labellum blade 42 × 31 mm when spread out, oval-shaped, with ca. 28 yellowish veins, cream-colored, obscurely trilobed, concave, with a conspicuous ventral groove and throat lined with yellow laterally; lateral lobes cream-colored, rounded, with ca. 12 yellowish cream-colored veins and forming a crest-like process at the column apex; lateral lobe margins entire, very slightly undulate, united to the column for 3/4 of its length (ca. 58 mm); apical lobe slightly rounded, ending in an acute, reflexed apex with an inconspicuous apical triangular cushion starting at 9 mm from the lip apex adorned with two lateral rows of digitiform papillae, each row with 8–12 papillae, and occasionally a third central row present with 3–4 papillae, lip apex tinged with green abaxially; apical lobe margin slightly undulate. Penicillate callus 4.5 mm long × 3 mm wide, well-defined at 22 mm from the apex, yellowish cream-colored, made up by 7 rows of flattened laciniae united to each other on the lateral margins, with the last row made up of multiple lines of grouped laciniae, forming a tuft. Column 62–67 mm long × 2–3 mm in diameter, merged at base with sepals and petals for 9–10 mm, cream-colored, slightly sinuous, thicker towards the apex and united to the labellum margins for the whole of its length (ca. 58 mm) and with a smooth ventral surface. Stigma 1 mm long × 2 mm wide, bilobed, each lobe quadrate-rectangular shaped, with digitiform lateral wings. Rostellum 3 mm long × 4 mm wide, yellowish cream-colored, convex and quadrate with rounded ends. Anther 5 mm long × 3 mm wide, versatile, saddle-shaped, yellowish cream-colored, with yellowish pollen grains aggregated in monads. Fruits 100–125 mm long × 9–13 mm in diameter, green, pendant, cylindrical, basally arcuate, appearance stout and rather short with a rounded and obscure calyculus when fully developed, dehiscent along two sutures, releasing a clear, brownish mucilaginous substance when dehiscing and strongly aromatic.

Etymology: — Vanilla javieri is dedicated to local Amazonian Vanilla co-researcher Javier Pineda Ferreira, who located the only known individual and passed away shortly after. The epithet is permitted by article 23 of the International Code of Botanical Nomenclature, and follows recommendations 23A.1, 60.8.(a) and 60C.1.a ( McNeill et al. 2012).

Distribution and habitat: — Vanilla javieri is only known from the type specimen. It was found growing in the understory of a 20–30 year old secondary growth forest near the road margin. The area where it occurs has been transformed since the construction of the road from Leticia to Tarapacá in the mid-1970´s. This area currently exhibits a matrix of rural settlements, agricultural crops and pastures for cattle ranching, as well as secondary growth forest and original forest cover.

Phenology: —The only known individual of this species has been observed in flower in January, April, May and September. The development of the inflorescence takes approximately 30 days before flower anthesis initiates. Flowers are ephemeral and abscise the next day if not effectively pollinated. Immature fruits become pendant as soon as pollination occurs. Fruit sets are generally low and only two natural pollination events have been observed from at least 50 flowers. Development of the fruit takes ca. 90 days before dehiscence occurs.

Conservation: —The new species is only represented by the type individual found in an area with high anthropogenic activities. This species is part of the group bearing aromatic fruits and is therefore an important wild relative of the widely cultivated V. planifolia . As a result, this species could be potentially sought-after by vanilla growers. Due to the aforementioned characteristics, along with its apparent rarity and narrow distribution in an area with high anthropogenic activities, it would be reasonable to include this species in the Critically Endangered (CR) category based on IUCN criteria [CR: A3c; B1ab (i,ii,iii,iv)].

Comments: —Among the species in the Vanilla planifolia group, it shares the small understory vine habit with V. appendiculata , V. cristagalli and V. ribeiroi . Additionally, the shape and size of the perianth segments in dissected flowers is very similar to V. appendiculata . Furthermore, V. javieri exhibits a column with a glabrous ventral surface, a trait found exclusively in V. appendiculata , V. capixaba and V. labelopapillata , within the V. planifolia group ( Flanagan et al. 2018). The combination of exclusively shared characteristics within the group suggests that its closest relatives are V. appendiculata and V. cristagalli . According to Fraga et al. (2017), V. cristagalli is a common species in the upper Solimoes river area (adjacent to the study area presented in this paper); however, it exhibits notable differences when contrasted against V. javieri . A comparison of notable characteristics among closely related species is presented in Table 1.

Some of the most distinctive characteristics of V. javieri when compared with other closely related members of its group are as follows. Vanilla appendiculata exhibits white flowers with yellow, papillose-barbellate lip ornamentation, described by Rolfe (1896) as “foliaceous appendages”. Vanilla appendiculata is easily distinguished among members of the Vanilla planifolia group because it is the only species that exhibits erect fruits. In detail, it differs from V. javieri in the conspicuous rows of warty papillae connecting the apical callus to the penicillate callus (vs. absent), the conspicuous warty texture of the inner surface of the claw (vs. lanuginose texture), the number of rows, size and shape of the laciniae of the penicillate callus, the shape of the papillae and the ornamentation pattern of the lip apex ( Fig. 4 ).

When compared with V. javieri , V. cristagalli bears leaves that are widest at half the blade length (vs. ¾ from the base in V. javieri ), larger and more congested floral bracts, more flowers per inflorescence (up to 40 vs. up to 20), the inner surface of the claw is warty (vs. lanuginose), the ventral surface of the column is covered by puberullent papillae (vs. completely glabrous), the penicillate callus is connected to the apical callus by 5 to 7 rows of tuberculate papillae (vs. absent) and it exhibits an emarginated (vs. slightly undulate) midlobe to the lip (RB 14512, RB 504109, Fraga et al. 2017). Householder et al. (2010) report the formation of mucilaginous substance between the splitting valves of dehiscing fruits, a trait that is also observed in V. javieri ; however, the fruits in V. cristagalli seem to occupy a terminal position. According to Soto-Arenas & Cribb (2010), V. cristato-callosa is synonymous with V. cristagalli , with the main difference in flower size. Furthermore, it differs from V. javieri in exhibiting oblanceolate leaves with longer petioles, more congested floral bracts, wider sepals and petals, notched lip apex and a shorter column (RB 37468).

Vanilla denshikoira is closely related to V. cristagalli ; however, it differs from V. javieri in the numerous elongated trichomes that adorn the lip apex ( Flanagan et al. 2018). Vanilla dubia is closely related to V. appendiculata and V. cristagalli , but it is easily distinguished by exhibiting oblanceolate leaves, an emarginated midlobe of the lip and thicker and shorter fruits when compared to the new species (RB 37014, Fraga et al. 2017). Vanilla schwackeana is a poorly known species that is also thought to be closely related to V. cristagalli , but with the lip ornamentation reduced to warty papillae ( Soto Arenas & Cribb 2010). Additionally, it exhibits leaves with a long, acuminate apex and fruits that are longer and less stout than in V. javieri (RB 87015). Vanilla dungsii occurs exclusively in the Brazilian Atlantic Forest and exhibits narrow-lanceolate leaves with a long-acuminate apex, internodes up to 16-18 cm, notched midlobe of the lip and rows of papillae connecting the lip apex with the penicillate callus (HB 59052, Fraga et al. 2017). Vanilla capixaba shares the glabrous ventral surface of the column with V. javieri ; however, it exhibits white flowers with a densely barbellate lip apex ( Fraga et al. 2017). Vanilla paulista exhibits a deeply emarginate midlobe to the lip and a column with a lanuginose ventral surface ( Fraga et al. 2017).

The remaining species in the V. planifolia group are not included in Table 1 due to their geographic distribution and distinctiveness from V. javieri . In this sense, Vanilla aspericaulis exhibits flowers with more papillae and a lanuginose ventral surface of the column (Sambin & Chiron 2017). Vanilla bahiana is reported to occur exclusively in the Brazilian Atlantic Forest and exhibits short xerophytic leaves, stout stems and large, greenish-yellow flowers ( Soto Arenas & Cribb 2010). Vanilla fimbriata and V. odorata are very closely related to each other and both exhibit oblanceolate leaves and fimbriate lip margins ( Soto Arenas & Cribb 2010). Vanilla helleri has abundant wax on the stem apices and whitish flowers with a bright yellow lip adorned with orange appendages on the midlobe ( Soto Arenas & Dressler 2010). Vanilla inornata exhibits lanceolate leaves and lacks papillae on the labellum (Sambin & Chiron 2017). Vanilla insignis is one of the largest members in the Orchidaceae family, with vigorous vines reaching up to 100 meters in length, flowers with apple-green tepals and dense, yellow-orange papillae covering the lip apex ( Soto Arenas & Dressler 2010). Vanilla labelopapillata exhibits linear-lanceolate leaves and a lip with fimbriate margins that is completely covered by seven rows of tuberculate yellow-orange papillae ( Koch et al. 2013). Vanilla phaeantha is common in the West Indies and has small xerophytic leaves and large flowers with a white lip adorned by yellow stripes ( Soto Arenas & Dressler 2010). Vanilla planifolia does not occur naturally in South America and the ornamentation of the lip is reduced to numerous warty appendages ( Soto Arenas & Cribb 2010). Vanilla ribeiroi presents reduced and xerophytic leaves, small greenish sepals and petals, concave column with a hirsute ventral surface and the distal half of the lip is completely covered by yellowish trichomes ( Householder et al. 2010). Finally, V. sotoarenasii exhibits warty appendages on the lip apex (Azofeifa-Bolaños et. al. 2017).

Figures

FIGURE 2. Vanilla javieri Barona-Colmenares.A. Dissected flower.B. Detail of column apex showing the versatile anther, rostellum and bilobed stigma (ventral view). C. Fruits. D. Terminal inflorescence with two flowers open simultaneously. E. Hemiepiphyte understory habit. (Drawn by the author from the holotype Barona-Colmenares & Pinedo 4666).

FIGURE 3. Vanilla javieri Barona-Colmenares. A. Greenish-cream colored flowers showing the ornamentation of the lip apex. B. Greenish flower buds exhibiting a basal, non-floriferous, subcordate foliaceous bract. C. Detail of coriaceous, abruptly mucronate leaves and pendant, arcuate, rather short and stout fruits. (Photographs by A.A. Barona-Colmenares).

FIGURE 4. Stereomicroscope photographs of Vanilla javieri Barona-Colmenares (A, B, C, D) and Vanilla appendiculata (E, F, G, H). A. Labellum claw. The inner surface of the labellum claw of V. javieri is lanuginose (A) versus warty in V. appendiculata (E). B. Penicillate callus. The callus of V. javieri (B) is less congested than the callus of V. appendiculata (F), with thicker and less numerous laciniae forming a tuft. Additionally, the veins in V. javieri are sinuous and contrast against the parallel veins in V. appendiculata. C. Vanilla javieri lacks appendages between the penicillate callus and the lip apex (C) versus few warty appendages connecting both in V. appendiculata (G). D. Ornamentation of the lip apex. Vanilla javieri exhibits few, small, digitiform papillae (D) versus longer and more numerous foliaceous appendages in V. appendiculata (H). Photographs:A.A. Barona-Colmenares & N. Oviedo (V. javieri) and A.A. Barona-Colmenares & J. Potosí (V. appendiculata).

FIGURE 5. Vanilla appendiculata Rolfe. A. Flower buds, showing white ovaries with a greenish apex. B. Flower and immature fruit. C. Lateral view of lip apex ornamentation with yellowish, barbellate, foliaceous appendages. D. The erect nature of the fruits. Photographs: A.A. Barona-Colmenares (A, B & D) and Goran Mihaijlovic (C).