Cyrtopodium valebellae J.A.N.Bat., 2023

Cyrtopodium valebellae J.A.N.Bat. , sp. nov. ( Figures 1–2 View FIGURE 1 View FIGURE 2 )

Type: — ARGENTINA. Tucumán: Tafi Viejo , ca. 50 km N de la ciudad capital, suelos áridos entre vegetación xerófila, 20 October 2004 (fl.), M. Valebella s.n. (holotype: CTES 399606 [ CTES0033367 ])

Similar to Cyrtopodium virescens in general morphology and flower colour, but distinguished by shorter and broader leaves when fully developed (length/width ratio of 10–12), petals reflexed in fully opened flowers, lip without isthmus separating median from lateral lobes, lip lateral lobes approximately the same size as the mid lobe and base constricted, mid lobe margin completely yellow and strongly verrucose and callus yellow, with a flat base and warty apex.

Description:— Terrestrial herb, occasionally rupicolous, seasonal. Roots ca. 4 mm wide, fasciculated, whitish, glabrous, numerous. Rhizome stiff, short, branched. Pseudobulbs 10–25 × 3.0– 7.5 cm, conical-fusiform, erect, plumpy, externally green to yellowish, arranged tightly on the rhizome, partially buried, with 9–12 nodes, leafless from the second year onwards, but then covered by sheaths that are gradually lost; sheaths appressed, imbricate, green when young, after dry grayish, acute, apex of the central vascular bundle stiff and peacked, semi-persistent. Leaves incompletely developed at flowering, up to 30 cm tall, 5 to 7 larger when fully developed, 20–60 × 2.0– 5.4 cm, length/width ratio of 10–12, linear to narrowly elliptic, with 3 prominent veins on the abaxial surface, margin smooth, apex acute, slightly plicate, coriaceous, articulate, deciduous. Inflorescences 0.5–1.3 m tall, lateral, erect, paniculate, rarely racemose, loosely multiflorous, longer than the leaves; peduncle 70–90 cm long, base 1 cm wide, green, with 3–4 sheaths; sheaths 2–4 × 1.7 cm, distanced from each other, appressed, elliptic, apiculate, slightly undulating, subtly multi-veined, yellow with reddish spots; secondary axis 1 to 5, 20–25 cm long, patent to ascending; floral bracts 12–20 × 5–10 mm, elliptic, acute, reflexed to patent, strongly wavy, similar in color to the sheaths, approximately half the length of the pediceled ovary. Flowers 8–74 per inflorescence, ca. 2.5–4.0 cm diam., patent to ascending, resupinate, yellowish with red or reddish brown spots. Pedicelate ovary 1.7–4.0 cm long, greenish yellowish. Sepals 13–20 × 7–10 mm, elliptic, margin markedly wavy, apex obtuse to subacute, apiculate; dorsal sepal erect, laterals slightly reflexed. Petals 11–20 × 7.5–12 mm, obovate to broadly elliptic, unguiculate, margin curly, apiculate, reflexed in fully opened flowers. Lip three-lobed, 9–13 mm long, when spread 14–18 mm wide between the apex of the side lobes, unguiculate, unguicule short, 2.5–3.0 × 2 mm; lateral lobes 5.0–6.5 × 6.0– 8.5 mm, erect, transversely broadly ovate (napiform), base narrow, margin upper portion entire to slightly wavy, apex curved, yellow with dense reddish macules concentrated on the margin; isthmus separating the lateral lobes from the mid lobe absent or inconspicuous; mid lobe 4.5–7.5 × 7–12 mm, transversely ovate, depressed to reniform, slightly emarginate and revolute, with warty lamellar margin, yellow with a dense reddish speckled base; callus (crest) ligular, from the middle of the unguicule to the base of the mid lobe, slightly sulcate on the upper side, notably warty, with some warts at the base of the lateral lobes, apex protruding, with ellipsoid warts, waxy, yellow with fine and spaced reddish dots. Column 5.5–8.0 × 2.5 mm, claviform, slightly arched, yellow, apex greenish; column foot claviform, 2.5–4.0 mm long, yellow; anther apical, 2-locular, globose, laterally enlarged, green; pollinia 2, subspherical, waxy, without caudicle; retinaculum triangular; stigma broad, orbicular, green. Capsule 6 × 3 cm, ellipsoidal, with three sutures and three prominent veins.

Distribution and ecology: — Cyrtopodium valebellae is so far known from the provinces of Jujuy, Salta, and Tucumán in northwestern Argentina and the departments of Tarija and Santa Cruz in southwestern Bolivia ( Figure 3 View FIGURE 3 ). This region mainly comprises the Southern Andean Yungas and marginally the Dry Chaco, the Central Andean Puna and the Bolivian Yungas ecoregions ( Olson et al. 2001), to which the species appears to be endemic. Cyrtopodium valebellae grows as a terrestrial, occasionally rupicolous plant in high and steep terrain areas. The species grows exposed to full sun, between 1100–1400 m a.s.l., forming isolated colonies among xerophytic vegetation of grasses, cacti and spiny bromeliads, as well as among herbs and shrubs in foothill forests. The soil usually consists of a sandy texture in combination with clay and silt in small proportions, slightly acidic pH and good organic matter content ( Sánchez and Valebella 2012). The species is subject to and withstand periodic fires. This species’ flowering occurs during October and November, comprising the end of the dry season and the beginning of the rainy season. Like other species of the genus that flower in the same period, growth begins with a new shoot that may or may not form an inflorescence. When present, the inflorescence growth outweighs that of the vegetative parts, which only become fully developed one or two months later during the rainy season. The leaves are deciduous, and only the fully developed pseudobulbs remain.

Etymology: —This new species is named in honour of the Argentine orchid naturalist Miriam Valebella, whose collections, documentation and accurate description first brought to light the existence of this new species.

Conservation Assessment: — Cyrtopodium valebellae is currently known from 13 records from 12 localities ( Table 1 View TABLE 1 ) and shows an EOO estimated at 70355 km 2 and an AOO of 44 km 2. Based on the IUCN Red List Categories and Criteria and its guidelines ( IUCN 2012, 2016), the new species can be tentatively classified as of least concern (LC) due to its wide geographic distribution and known to exist at more than 10 locations, some of which are located within legally protected areas, such as Parque Nacional Calilegua and Parque Nacional El Rey in Argentina, and Parque Nacional y Área Natural de Manejo Integrado Amboró in Bolivia.

Additional specimens examined (Paratypes): — ARGENTINA. Jujuy: Departamento Ledesma, camino a Valle Grande, 14 November 1992 (fl.), R. Kiesling et al. 8253 (SI); Parque Nacional Calilegua, Mesada de las Colmenas, 1150 m, 12 October 1997 (fl.), A.E. Johnson & P. Giorgis 756 (SI 53345); Tucumán: Departamento Burruyacú, 3-4 km camino al Cerro Medina, costeando el Río Nío, 20 October 1965 (fl.), P.R. Legname & A.R. Cuezzo 5499 (LIL 474624); Río Nío, 23 October 2009 (fl.), M. Valebella 091-023 (LIL 610733), Río Nío, 21 October 2010 (fl.), M. Valebella 010-981 (CTES0028946); Sierra del Nogalito, 1200 m, 10 November 2005 (fl.), A. Grau s.n. (LIL 607339); Salta: Departamento Anta: Parque Nacional El Rey, October 2005, S. Chalukián s.n. (BAA). BOLIVIA. Tarija: route Entre Rios – Villa Montes, 1400 m, falaise rocheuse avec végétation herbacée, 10 November 1993 (fl.), F. Billiet & B. Jadin 6152 (MO 6043247).

Taxonomic discussion: —As far as we could determine, C. valebellae was first collected by Legname and Cuezzo in 1965 in the province of Tucumán in northwestern Argentina. This specimen and a few others in herbaria were previously identified as C. punctatum ( Linnaeus 1759: 1246) Lindley (1833: 188) , C. paniculatum or C. virescens Reichenbach f. (1881: 89) . The new species is remarkably similar in general morphology and flower colour to C. virescens but differs in several details of floral morphology, particularly in the lip ( Table 2 View TABLE 2 ). In C. valebellae the petals are reflexed in fully opened flowers ( Figure 2F View FIGURE 2 ) (vs. not reflexed in C. virescens , Figure 4A View FIGURE 4 ), the lip lacks an isthmus separating the mid lobe from lateral lobes ( Figure 2H–J View FIGURE 2 ) (vs. with well-developed isthmus), the lip lateral lobes are approximately the same size as the mid lobe and have a constricted base ( Figure 2H–J View FIGURE 2 ) (vs. lateral lobes smaller than the mid lobe and base not or little constricted), the lip mid lobe margin is entirely yellow and strongly verrucose ( Figures 2E, 2H, 2K View FIGURE 2 ) (vs. reddish and smooth or at most slightly verrucose, Figure 4B View FIGURE 4 ) and the callus mostly yellow, formed by a flat base and apex with ellipsoid warts ( Figures 2E, 2H, 2L View FIGURE 2 ) (vs. markedly grooved throughout and mostly white with reddish spots, Figure 4B View FIGURE 4 ). Finally, in C. valebellae the leaves are shorter (20–60 cm long) and broader (2.0– 5.4 cm) when fully developed ( Figure 2D View FIGURE 2 , Table 2 View TABLE 2 ), with a length/width ratio of 10–12 (vs. longer and narrower in C. virescens ( Figure 4C View FIGURE 4 ), 42–106 × 2.0– 2.8 cm and length/width ratio of 21–44). Additional photographs and a line drawing of C. valebellae were published by Sánchez and Valebella (2012, fig. 1, fig. 2A–D) as C. paniculatum .

In addition to texture and colour, the margin of the mid lobe of the lip shows other differences between the two species, although these are less evident. In C. virescens , the fold at the apex of the mid lobe is very pronounced so that the margins of each side often meet, and the whole margin is often folded backwards (revolute) to a greater or lesser extent, while in C. valebellae , the fold is less pronounced and the mid lobe is all more or less flat. Similarly to C. virescens , the upper margin of the lateral lobes of the lip may be slightly curly in the new species.

Sánchez and Valebella (2012) identified the new species as C. paniculatum and were followed by subsequent authors ( Zuloaga et al. 2019). However, C. paniculatum differs in the rupicolous habit, pseudobulbs 25–60 cm long ( Figure 4D View FIGURE 4 , Table 2 View TABLE 2 ), flower colour and geographical distribution, among some other characters. In C. paniculatum , the flowers are greenish or greenish-yellow, the sepals are profusely stained with brown, the spots or blotches of the petals are concentrated in the abaxial surface, and the mid lobe has a wide orange band at its margin ( Figures 4E–F View FIGURE 4 ). In terms of distribution, C. paniculatum occurs in the Andes from Peru to Venezuela. There are also records for Bolivia ( Vásquez et al. 2003), and although the occurrence is possible, we could not find any material of the species from Bolivia. The few samples from Bolivia that we examined identified as C. paniculatum are C. saintlegerianum Reichenbach f. (1885: 301) , an epiphytic species similar to C. punctatum and C. pflanzii Schlechter (1922: 49) . The records of C. paniculatum for Argentina represent specimens of C. valebellae or C. saintlegerianum . Cyrtopodium paniculatum forms a complex together with C. hosltii Menezes (1993: 149) , C. naiguatae Schlechter (1919: 43) , C. graniticum Romero-González (1999: 512) , C. macrobulbon ( La Llave & Lexarza 1825: 42) Romero-González & Fernández-Concha (1999: 331) , and C. willmorei Knowles & Westcott (1837: 7) and the exact identity, morphological variability, geographic distribution of each and differentiation between them is not yet fully understood. Lastly, the identification as C. punctatum is unwarranted since C. valebellae is distinguished by its terrestrial or rupicolous habit (vs. epiphytic), bright yellow flowers spotted with red (vs. greenish or yellowish stained with brown) and parallelled lateral lobes of the lip (vs. arched towards each other, often meeting above the column).

Cyrtopodium valebellae is similar in vegetative morphology to other terrestrial species in the genus characterized by medium-sized (10–25 cm long), aerial pseudobulbs, such as C. virescens , C. eugenii Reichenbach f. (1881: 89) , C. vernnum Reichenbach f. (1881: 89) and C. parviflorum . However, it is distinguished from these, and other species by the combination of flower colour, lip morphology and geographical distribution restricted to the Southern Andean Yungas and Chaco Serrano ecoregions of northern Argentina and southwestern Bolivia.

The southern central Andes (south-western Bolivia and north-western Argentina) comprises a separate unit among other South American arid plant formations ( López et al. 2006) and is known for the high number of endemic vascular plants (ca. 616 species), of which more than 2/3 are restricted to semi-desert and semi-arid habitats at middle elevations between 1500–3500 m a.s.l. ( Aagesen et al. 2012). Asteraceae (126 spp.) and Cactaceae (75 spp.) are the families with the highest number of endemic species, while Orchidaceae has only six endemic species, most of the genus Chloraea Lindley (1827: 47) ( Aagesen et al. 2012). The description of C. valebellae now adds one more species to this list, reinforcing the singularity of this region.