Encyclia inopinata (Orchidaceae, Laeliinae) a new species from Mexico

Abstract A new species of Encyclia from Mexico, Encyclia inopinata, is described and illustrated. This species is similar to Encyclia diota but it can be distinguished by its usually more robust plants with 2–3 leaves per pseudobulb and its flowers with longer and narrower sepals (1.8±0.1 × 0.63±0.03 cm in Encyclia inopinata versus 1.48 ±0.14 × 0.65±0.06 cm in Encyclia diota) and petals (1.7±0.05 × 0.59±0.05 cm in Encyclia inopinata vs. 1.36 ±0.19 × 0.81±0.13 cm in Encyclia diota), and the labellum with narrower lateral lobes (0.18±0.02 cm in Encyclia inopinata vs. 0.41±0.10 cm in Encyclia diota). Other characters that differentiate these two species are the coriaceous sepals, pink callus, and white anther of Encyclia inopinata (versus fleshy-leathery sepals, white callus, and yellow anther of Encyclia diota). The new species can be found in deciduous forests along the Pacific slope of Oaxaca state, near of the border with Guerrero state, at about 1200 m. It blooms between March and July.


Introduction
Encyclia is a Neotropical genus ranging from Florida in the southern United States of America south to the Salta province in northern Argentina; the distribution includes both the continental areas and the West Indies. Species of the genus are usually found in seasonally dry ecosystems below 1200 m, although some can be found at altitudes of up to 2500 m (van den Berg and Carnevali 2005). According to preliminary phylogenetic analyses, the Encyclia diota complex has at least three species, and is morphologically characterized by pyriform pseudobulbs, linear-oblong, relatively wide, and coriaceous leaves, a fractifl ex infl orescence with loosely arranged, relatively large, leathery to fl eshy-leathery showy fl owers, a smooth pedicellate ovary; the sepals and petals are of variable colors, from bronze or ocher to dark chocolate; the labellum is conspicuously trilobulate, the lateral lobes are patent at the apical half or only slightly recurved distally; the callus is glabrous and the column is straight. One of the most distinctive characters of this species complex is the yellow labellum with crimson to reddish brown lines. Members of the Encyclia diota complex tends to occupy dry, seasonally deciduous forests, from Mexico (northwestern Oaxaca) to northern Nicaragua, generally at medium to high altitudes (600-2000 m).
Historically, whether Encyclia diota represents one or more species has generated considerable disagreement. Some taxonomists propose the existence of at least two species (E. diota and E. insidiosa (Rchb. f.) Schltr.), a view we support; others suggest the complex consists of one species (consult Dressler 1976, for a historical review). Th ese discrepancies are reasonable because, on the one hand, plants from diff erent populations are, at fi rst, diffi cult to distinguish from each other but, on the other hand, careful examination can show clear and consistent morphological diff erences between populations, strongly associated with a geographical component, a biological scenario that may require more than one species to be understood (Leopardi-Verde et al. in prep.).
We recently detected yet another species in this complex that shows diff erences in shape, size, and colors from others in the complex, which is here described and illustrated.

Materials and methods
Live plants were studied ex situ, from collections of German Carnevali and the Missouri Botanical Garden. We also examined 49 specimens housed at herbaria AMES, AMO, CICY, F, MEXU, MO, TEFH and W. Of these, 23 were of Encyclia diota and 21 of E. insidiosa. Acronyms of the herbaria follows Th iers (2013). Th e characters (vege tative and fl oral) used to describe the new species were determined from the fresh and dry specimens. In case of fresh materials and dry specimens, pictures of whole samples were taken with a FUJIFILM FinePix S200EXR digital camera. Fresh fl owers were dissected and digitized in a XL1600 EPSON scanner. For rehydratation, herborized fl owers were placed in a commercial detergent with ammonia for about 30-45 min, and then left in water for about one hour; afterwards they were dissected and mounted in a glass slide to digitize in a XL1600 EPSON scanner. Each specimen or its details were digitized with a scale. Th e cardboard fi le mounted records were scanned directly. All measures (height, length and width of pseudobulb, leaves, length of the infl orescence and its branches, etc.) were taken with the software ImageJ (Schneider 2012).

Encyclia inopinata
Description. Epiphytic herb, 30-42 cm tall, up to 80-90 cm including the infl orescence. Rhizome short and fi brous. Pseudobulbs 5.0-8.0 × 3.9-4.5 cm, clustered, ovoid to pyriform, apically 2-3-leaved, green and smooth when young, covered with papery sheaths that eventually defi brate and disintegrate, when old sometimes stained with maroon or purple. Leaves 34-38 × 2.8-3.5 cm, linear-oblong to oblong-ligulate, subacute, coriaceous, conduplicate at the base, dark green to purple tinged with central nerve marked mainly on abaxial face. Infl orescence 60-90 cm long, terminal, erect, racemose or paniculated, when panicles with 3-5 branches of 2.6-11 cm long, each branch with 3-8 fl owers, the entire infl orescence with up to 50 fl owers; peduncle slender but strong, smooth, usually green, with adppressed sheaths of 0.9-1.4 cm long, that become smaller toward the apex; bracts inconspicuous, triangular of 0.2-0.5 cm long; pedicellate ovary 1.3-1.7 cm long, smooth. Flowers resupinate, showy, 3.0-3.4 cm diameter (between the tips of the petals); sepals and petals coriaceous, bronzegreen, veins marked with dark purple lines; labellum green towards the base and pale, dull yellow-green toward the apex, with reddish-brown lines, the central lobe with well developed keels that reach the apex, of these the most conspicuous is the central one, lateral lobes with reddish brown lines that extend almost to the apex, lateral lobes free of the central lobe, pale pink callus; column creamy white with reddish-brown spots and lines; sepals similar, oblanceolate, acute, the laterals oblique, dorsal sepal 1.7-1.9 × 0.60-0.65 cm, lateral sepals 1.7-1.9 × 0.60-0.65 cm; petals 1.65-1.73 × 0.57-0.60 cm, obovate-spatulate to narrowly obovate-spatulate, with a conspicuous claw towards the base of 0.64-0.68 × 0.10-0.16 cm, acute to acuminate. Labellum 1.25-1.35 × 0.9-1.1 cm, 3-lobulate, free of the column except at the base, central lobe 0.5-0.7 × 0.6-0.8 cm, ovate, shortly acuminate; lateral lobes 0.80-0.90 cm long, 0.17-0.20 cm wide in the middle portion and 0.4-0.5 cm wide in the portion that lies between the base of the labellum and which separates within the central lobe, oblong, rounded towards the apex, separated of the central lobe by a sinus of ca. 0.1 cm width; in natural position lateral lobes are refl exed at the apex, and embrace the column; callus 0.45-0.49 × 0.24-0.28 cm, sub-rhombic, hirsute, consisting of two keels separated by a conspicuous sulcus, which widens slightly and forms a fovea, these keels converge towards the apex of the callus extending into the blade of the central lobe of the labellum as a keel that reaches the apex. Column 0.6-0.7 × 0.2-0.3 cm, semi-cylindrical, straight, ventral outline slightly clavate, wingless; anther 0.18-0.22 × 0.18-0.22 cm, white; pollinia 4, yellow, separated into groups of two, yellow caudicles; stigmatic surface 0.23-0.29 × 0.19-0.24 cm, subquadrate; rostellum 0.060-0.064 × 0.149-0.153 cm, semicircular. Capsule not seen (Figure 1 A-J). Distribution and ecology. Encyclia inopinata has been reported only from Oaxaca state near the pacifi c slope from north of Puerto Escondido to north of San Juan Cacauatepec (near the border with the Guerrero state) in deciduous forest, ca. 1200 m (Figure 2). It usually grows as a lithophyte. Th is species appears to be rare. It blooms between March and July.
Etymology. From the Latin inopinatus, unexpected, in reference to the surprise that we felt when fi rst seeing the new species in bloom and realizing that it was an undescribed species in the E. diota complex.
Comments. Dressler and Pollard (1974: 130) suggested that a population of Encyclia aenicta in Oaxaca "tend[s] to have longer and wider lateral lobes and also tends to be more yellowish in color, suggesting, some hybridization with E. diota." Th ese authors implied that, size-wise, this entity was more similar to E. aenicta than to E. diota. Th e locality and characters showed by Dressler and Pollard (1974: 130) strongly suggests that they were referring to a population of what is here proposed as E. inopinata. Another source containing information about an entity similar to E. inopinata is the "Notes on Encyclia", and unpublished manuscript of G. Pollard (housed at the AMO library). Tome 4 ("N to O"), page 69, describes a specimen that matches well our concept of E. inopinata. Th is manuscript also has additional cards (E-34 y E-45, p. 70 and 72 respectively) and pictures (p. 71) showing specimens that, again, match well the new species proposed herein.
Hybridization, most likely, has played an important role in the evolution and diversifi cation of Encyclia (Dressler andPollard 1974, Leopardi-Verde 2014). However, in this case, it is diffi cult to support the hypothesis of a cross between E. diota and E. aenicta as the origin of E. inopinata (Dressler and Pollard 1974: 130). We strongly reject this hypothesis considering that there is no contact zone between these taxa ( Figure 2) and, in addition, the lack of morphological intermediacy between the hypothetical parents of such hybrid. Finally, Encyclia inopinata resembles E. diota in fl oral colors, but the texture and proportions of the fl owers are very diff erent (see diagnosis above). Encyclia inopinata is also similar to E. insidiosa, an entity from Central America (ranges from Nicaragua to northern Guatemala). Encyclia inopinata and E. insidiosa can be discriminated by the tendency of the second to have sepals and petals dirty ocher to chocolate, whereas in E. inopinata these structures are bronze-green. Th e anther in E. insidiosa is yellow whereas in E. inopinata it is white or creamy white. Th e sepals and petals in E. insidiosa are shorter than in E. inopinata (1.54-1.68 cm versus 1.7-1.9 cm). Th e labellum of E. insidiosa and E. inopinata are similar in length, but in the former is wider (1.22-1.38 × 1.31-1.61 cm versus 1.25-1.35 × vs. 0.9-1.1 cm).