Barkeria wixarika C.E. León-Peralta & E.A. Pérez-García, 2024

León-Peralta, Cekouat E., Jones, Jason, Reynaud, Sergio & Pérez-García, Eduardo A., 2024, Barkeria wixarika (Laeliinae, Epidendroideae, Orchidaceae), a new species from Nayarit, Mexico, Phytotaxa 674 (3), pp. 265-274 : 266-271

Barkeria wixarika C.E. León-Peralta & E.A. Pérez-García , sp. nov. ( Figure 1 )

Type:— MEXICO: Nayarit: Santa María del Oro Municipality, on Crescentia alata in tropical deciduous forest, 800 m, 17 March 2024, J. Jones sub C. León-Peralta 370 (holotype: MEXU!) .

Epiphytic plant resembling Barkeria uniflora , but differs in its simple raceme (vs. double raceme) inflorescences, lanceolate to elliptical (vs. elliptical-obovate) petals, oblong-elliptic (vs. spathulate) column lacking papillae and ocellate spots (vs. papillose, ocellated), and involute column wings (vs. extended).

Description:—Epiphytic, compact, caespitose, erect, deciduous herb, 9.5–38.0 cm in height including the inflorescence. Roots numerous, simple or branched in the terminal part, fleshy, terete or slightly flattened, 2–4 mm in diameter. Stem slightly thickened, subterete, a little laterally compressed, 4–9 mm in diameter and 2–13(–16) cm in height, covered by tight, scarious sheaths, usually with reddish-purple dots and streaks. Leaves 3–5, distichous, deciduous, slightly reflexed, articulated to the stem sheaths, leathery-fleshy, flexible, lanceolate, acuminate, dorsally carinate, olive green, sometimes speckled with red-purple, 0.6–2.0 cm × 2.5–11.0 cm. Inflorescence from the mature stem, apical, erect, a simple raceme 5–24 cm long; peduncle elongated, subterete, 1.5–4.0 mm in diameter, 5.0– 16.5 cm long, green, with reddish spots, covered by scarious bracts; bracts 1.0– 4.5 cm long. Floral bracts concave, triangular-lanceolate, acuminate, drying before anthesis, papery, brown, 3–12 mm × 1.5–3.0 mm, progressively smaller, adpressed to the ovary. Flowers 1–4(–7) flowers, all open at the same time, resupinate, odorless, 44–50(–55) mm in diameter; sepals and petals extended, inflexed, concave, arranged in a plane superior to the lip and column; sepals and petals white-pale pink, slightly lighter on the inner surface, lip white-pale pink, with magenta lines in the portion below the column, the apex with a magenta elliptical-cordate blotch; column white-pale pink on both surfaces, the dorsal surface with reddish spots on the central axis; anther yellow-cream. Ovary pedicellate, arched to sigmoid, thin, terete, thickened distally, green blotched with purple, inconspicuously 6-sulcate, 15–25 mm × 1.5 mm in diameter at the pedicel and 2.5 mm at the apex. Sepals truncated at the base, slightly carinate on the external surface, dorsal sepal elliptic, acute, acuminate, 20–28 × 7–11 mm. Lateral sepals elliptic-lanceolate, slightly falcate, acute, acuminate, forming a right to obtuse angle when flattened, 24–30 × 6–12 mm. Petals obovate, acute, acuminate, attenuated towards the base, approximately on the same horizontal axis, incurved and slightly concave, slightly sulcate on the inner surface, 21–27 × 7–14 mm. Lip adnate to the base of the column ca. 2 mm, forming a dry cuniculus that slightly penetrates the ovary; oblong to obovate, the base obtuse, the apex rounded, slightly acuminate, the basal margins very slightly inflexed, lateral margins extended or sometimes folded downwards, the entire lip 20–28(–31) × 15–22(–24) mm. Ornamentations little developed, at the base of the lip formed by two thickened, flattened and fleshy keels that form a very low, narrow, sulcate, triangular-shaped basin ending in 1 tiny tooth, followed by a very small elliptical depression; at the apex one small keel. Column appressed against the lip, straight, dorsoventrally compressed, generally oblong-obovate, slightly pandurate, with two membranous, semi-elliptic, involute, smooth, thin wings; the ventral surface very slightly sulcate, with two elliptical depressions below the wings; the entire column 14–15 mm long, 6–9 mm wide, the base 4 mm wide, the wings ca. 8 × 2 mm. Clinandrium a transversely rectangular cavity, ca. 3 mm wide and 1 mm deep, the upper margin with an obtuse-rounded, inflexed middle tooth, the sides limited by 2 fleshy, erect, straight-rounded lobes. Stigmatic cavity depressed, trapezoid-triangular, the lateral lobes visible in the lower half, united by ca. 1 mm, viscous, ca. 3 × 2 mm. Rostelum a thick, concave, transversely semi-elliptical, cream-white lamina, ca. 2 mm wide, viscarium produced on the abaxial surface. Anther cap trapezoidal-cordiform, dorsoventrally compressed, slightly emarginate at the apex, the wings very little raised without exceeding the limit of the clinandrium, 4-locular, fleshy, ca. 3 × 2 mm. Pollinarium with 4 laterally compressed pollinia, in 2 pairs, intense yellow, obovate-semi-elliptical, each pollinia ca. 1 × 0.6 mm; united to granular caudicles glued longitudinally in pairs, the apices bulging, ca. 1.5 mm long. Capsule globose-elliptical, 22–28 × 11–13 mm.

Distribution and Ecology:—Endemic to the state of Nayarit, Mexico, Barkeria wixarika is currently known only from the Río Santiago-Aguamilpa basin, within Santa María del Oro and Del Nayar municipalities ( Figure 2 ). It is not abundant in known localities, although potential habitat extends at least 60 km along the river basin. Barkeria wixarika is an epiphytic, deciduous herb, found in tropical dry forests or in riparian forest, at elevations between 190 and 1,000 m. It flowers during the rainy season, from July to September. The species exhibits a strong preference for Crescentia alata Kunth (in Humboldt et al. 1818: 158) trees within pastures. Less frequent phorophytes include Guazuma ulmifolia Lamarck (1789: 52) and species of Pseudobombax Dugand (1943: 65) , Opuntia Miller (1754: 974) , in riparian forests. Barkeria wixarika coexist with Trichocentrum pendulum (Carnevali & Cetzal in Carnevali et al. 2010: 171) R.Jiménez & Solano in Solano et al. (2011: 54).

Etymology:—The specific epithet “ wixarika ” [viˈraɾika] honors the Wixárika, the predominant native culture in the Mexican state of Nayarit. The meaning of “ wixarika ” is debated, with interpretations ranging from “healer” ( Olguín 2008) to “people of great heart or great feelings” ( Chapela 2007). However, native speakers translate it as “web of dreams or knowledge” (X. Bautista, pers. comm.). The Wixárika people, self-called wixaritari and referred to as “huicholes” in Spanish, are native to western Mexico (mainly the states of Jalisco, Nayarit and Durango). Although they represent less than 2% of the Mexican Indigenous population (around 43,929 people; Neurath 2003), their vibrant culture and crafts are widely celebrated in Mexico.

Additional specimens examined (paratypes):— MEXICO. Nayarit: 19 August 1993, G. Flores-Franco et al. 2736 ( MEXU [ 602891 ]!) , 15–16 September 1960, R. McVaugh 19052 ( F [ 1575058 ]! MICH [ 1646952 ]) , 20 July 2024, C.E. León-Peralta et al. 370–373 ( MEXU!) .

Other records:— MEXICO: Nayarit: 06 September 2023, W. Medina s.n. ( AMO, digital photo) .

Conservation status:—Based on IUCN criteria we suggest Barkeria wixarika to be classified as Endangered (EN) due to its restricted distribution with calculated EOO= 636 km 2 and AOO = 12 km 2, along with its reduced number of localities (three found so far) which are being subject to land use change for agriculture and livestock. The populations of the new species are scattered in disturbed areas along the Río Santiago-Aguamilpa basin and the plants are not abundant, with a couple dozen individuals on particular phorophytes, especially in pastures. It is difficult to estimate a population size number, but from the abundance we have observed, we believe it is likely to be less than 10 thousand plants. Barkeria species are easy to propagate using in vitro techniques (i.e. Gómez-Almazán et al. 2024), so we recommend its reproduction from seeds to ensure its ex situ conservation and to discourage illegal trading.

Taxonmic Discussion:—Previous collections of Barkeria wixarika were deposited in herbaria as B. uniflora (i.e. McVaugh 19052 F) or B. barkeriola (i.e. Flores-Franco et al. 2736 MEXU). Indeed, the new species belongs to the “ uniflora ” group of Barkeria , which includes species with cane-like stems, reddish spots and stripes on the leaves, inflorescences and ovaries, and incurved pale-pink sepals and petals ( León-Peralta 2022). In particular, it resembles B. uniflora ( Figure 3A–F ), B. uruapani ( Figure 3G–I ), and B. barkeriola ( Figure 3J–L ); however, it differs from those species in the characters listed in Table 1 .

The plants of Barkeria wixarika are smaller than similar species, with stems typically under 15 cm and racemes bearing up to eight flowers, contrasting with the larger, branched inflorescences of B. uniflora and B. uruapani . Its flowers are distinguished from the geographically closer B. barkeriola by their larger size, the right-obtuse angle between the lateral sepals and the broader lip. The oblong column distinguishes B. wixarika from B. uruapani .

Flowers of Barkeria wixarika resemble those of B. uniflora , but differ in petal shape (lanceolate-elliptical vs. elliptical-obovate), the oblong-elliptic column without papillae on the ventral surface and lacking ocellated spots on top (vs. spathulate with abundant papillae on the ventral surface and marked eye-like spots), and the involute column wings (vs. extended). In particular, the color pattern of the flowers of B. wixarika contrasts with that of B. uniflora in the paler column, sometimes almost completely white ( Figure 4 ), especially in comparison with the plants of the Pacific Coast ( Figure 3A–C ), which have columns profusely covered with red spots, and a blotch on the lip larger than in the plants from the Balsas River Basin ( Figure 3D–F ).

Barkeria wixarika exhibits an unusually early flowering period compared to other “ uniflora ” group members, coinciding with the peak of the rainy season. Flowering timing may vary based on annual precipitation patterns, but we have found plants flowering from late June to September. Although this period overlaps with the flowering of B. barkeriola and B. uruapani , it is quite contrasting to that of B. uniflora , from late October to January, supporting reproductive isolation from that species.

So far, no natural hybrids between Barkeria species have been described. The pollinators of B. barkeriola and B. uniflora are unknown and the artificial hybrid using both species as parents ( Barkeria × Robert Marsh) has a phenotype strikingly like B. uniflora (see figure 7 in León-Peralta et al. 2021), having rounded petals and wide column wings with ocellate spots at the tip, characters that differentiate it from B. wixarika . Furthermore, ongoing phylogenomic studies using both organellar and nuclear loci recover B. wixarika as sister to B. barkeriola , discarding the possibility of a hybrid origin of the newly described species (León-Peralta in prep.).

Figures

FIGURE 1. Barkeria wixarika C.E. León-Peralta & E.A. Pérez-García. A. Flowering plant. B. Flower. C. Dissected perianth. D. Lip and column in normal position, front and lateral views. E. Column, front, lateral and back views. F. Anther cap, dorsal and ventral views. G. Pollinarium. Plate based on the type. Photos by CELP.

FIGURE 2. Geographic distribution of Barkeria wixarika and related species in Mexico.

FIGURE 3. Barkeria species similar to B. wixarika. A–C. B. uniflora from Jalisco (Pacific Coast). D–F. B. uniflora from State of Mexico (Balsas River Basin). G–I. B. uruapani from Michoacán. J–L. B. barkeriola from Jalisco. A, D, G, J. Flowers. B, E, H, I. Dissected perianths. C, F, I, L. Columns, dorsal, ventral and lateral views. Photos by CELP.

FIGURE 4. Floral variation in Barkeria wixarika. All plants from the type locality. Photos by JJ.