Cyrtopodium izaguirreae A.González & J.A.N.Bat., 2023

Batista, João A. N., González, Andrés & Cruz-Lustre, Gabriela, 2023, A new overlooked species and a new record of Cyrtopodium (Cymbidieae, Orchidaceae) from Uruguay, Phytotaxa 613 (2), pp. 127-139 : 129-135

publication ID	https://doi.org/ 10.11646/phytotaxa.613.2.2
DOI	https://doi.org/10.5281/zenodo.8355835
persistent identifier	https://treatment.plazi.org/id/03F087A2-4935-030F-C4A2-FCEEFE83FE3F
treatment provided by	Plazi
scientific name	Cyrtopodium izaguirreae A.González & J.A.N.Bat.
status	sp. nov.

Treatment

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

Type: — URUGUAY. Rivera: Bajada de Pena , ladera de arenisca, 20 Nov 2022 (fl.), A. González, J.L. Antúnez, M.H. Rosales & M. Gariglio s.n. (holotype: MHNH 23501 !; isotypes: BHCB 212936!, CEN)

Similar to C. kleinii in vegetative morphology and size of flowers, but distinguished by the lip midlobe and lateral lobes pinkish or purple, lip lateral lobes 7–8 mm long, falcate, and lip midlobe 5–6 × 7–8 mm, larger than the lateral lobes, transversely oblate to kidney-shaped.

Description: —Terriculous herb. Roots 4–5 mm wide, fleshy, whitish, glabrous, many. Pseudobulbs 3.5–5.0 × 1.5– 2.0 cm, fusiform, partially buried, apexes exposed, leafless from the second year onwards, densely inserted on a rhizome in which those from previous years remain, wrapped in abundant fibrous remains from the bases of old leaf sheaths, greenish-brown when exposed to sun light. Leaves 4–8, present at flowering, 10–56 × 0.9–2.2 cm, linear, acuminate, base conduplicate, plicate, multi-veined, with 3 prominent veins on the abaxial surface, coriaceous, articulate, articulation 3–4 cm from the apex of the pseudobulb. Inflorescence lateral, erect, usually simple, lax, 35–65 cm high, generally longer than the leaves, originating laterally in the axil of the first or second leaf sheath, green, occasionally with 1–3 lateral branches 15–28 cm long; peduncle with two or three sheath-like bracts, adpressed, 1.8–3.8 × 0.3–0.8 cm, membranaceous, shorter than the internodes, apiculate, decreasing in size towards the apex of the inflorescence; rachis 15–35 cm long, 2–4 cm wide including the flowers; floral bracts 5–28 × 3–5 mm, lanceolate, acuminate, gradually decreasing towards the apex of the inflorescence, with brownish-purple spots over a greenish background; ovary with pedicel 2.0– 2.7 cm long; pedicel 1.0– 1.5 cm long, patent or somewhat nutating; ovary 1.0– 1.3 cm long, conical, greenish. Flowers 18–22, small. Sepals slightly concave, ovate to lanceolate-ovate, occasionally broadly ovate, apiculate, margins discreetly undulate, base completely lilac or white with lilac dots, from the middle onwards with brown-lilac dots that converge towards the apex or completely brown; dorsal sepal 8–12 × 5.5–6.0 mm, oval, multiveined, rounded at the base, briefly apiculate, margins somewhat ruffled, entirely purple or white with lilac dots; lateral sepals 8–11 × 4.5–6.0 mm, oblique, oval, somewhat narrower than the dorsal sepal. Petals 8.5–10 × 6.5–7.0 mm, slightly concave, towards aging becoming slightly reflexed from the middle to the apex, broadly oval to lanceolate-ovate, horizontal, margins barely crenate, apex subapiculate, base white lilac or yellowish-white, middle part completely brownish or with purple spots, this color becoming uniform at the apex. Lip three-lobed, 12–14 mm long, when spread 10–12 mm wide between the apex of the side lobes, base and unguicule adaxially slight pubescenct; base 1.0– 1.5 mm long, shortly unguiculate, arched, with 2–4 parallel, white callosities, from the base to the separation limit of the lateral lobes; lateral lobes 7–8 × 2.0– 2.5 mm, erect, oblong, falcate, pinkish; callus (crest) oblong, strongly bi or tri-parted, verrucose, with a central longitudinal groove, whitish, extending longitudinally from the base of the midlobe to the unguicule, usually extending laterally to the base of the lateral lobes, base yellow, the verrucae white towards the apex; isthmus separating the lateral lobes from the midlobe usually evident, 1–1.5 mm long; midlobe 5–6 × 7–8 mm, transversely oblate to kidney-shaped, base slightly constricted, apex rounded, emarginate, margins curly, purple. Column 5.0–5.5 × 1.5–2.0 mm, slightly arched, trigonous, base white to light purple, middle white to whitepurple and towards the apex purple to greenish-purple; column foot 2.5 mm long, purple. Anther 2 mm, apiculate, yellow, apex gibbous, green; pollinia 1.2 mm long, ovoid, waxy, sulcate, without caudicle, attached to a triangular, hyaline stipe. Capsule 3–5 × 1.5 cm, dehiscent, pendulous, ellipsoid, dark brown, in which withered remains of the flower persist.

Distribution and ecology: — Cyrtopodium izaguirreae is a rare taxon currently known only from two populations close to each other, in the Rivera Department, northern Uruguay ( Figure 3 View FIGURE 3 ). Probably the species should be expected for neighboring regions of the state of Rio Grande do Sul, in southern Brazil. A particularly potential area is the Area de Proteç„o Ambiental de Ibirapuit„, located immediately on the Brazilian side of the border, comprising an area of 316,792 ha including habitats similar to those found on the Uruguayan side where C. izaguirreae occurs, such as hillsides, with shallow soils and rocky outcrops. Cyrtopodium izaguirreae grows in open grassland on north-facing, well-drained slopes at an elevation of 200–240 m in the Bosques Serranos of northern Uruguay ( Figure 1A View FIGURE 1 ), a vegetation type found on the slopes of hillsides with shrubby vegetation ( Pérez et al. 2020), in the Basaltic Slope ecoregion (Cuesta basáltica; Brazeiro et al. 2015). The soil is sandy, dry, usually with rocks on the surface ( Figure 1B View FIGURE 1 ) and often grows associated with Asteropsis megapotamica ( Sprengel 1826: 526) Marchesi in Bonifacino et al. (2009: 3), Grazielia intermedia ( Candolle 1836: 148) King & Robinson (1972: 306) , Schlechtendalia luzulifolia Lessing (1830: 243) (Asteraceae) , Betencourtia australis ( Malme 1931: 35) Queiroz et al. (2020: 87) (Fabaceae) , Axonopus argentinus Parodi (1938: 15) and Trachypogon spicatus ( Linnaeus 1782: 111) Kuntze (1891: 794) (Poaceae) . Flowering occurs in November and December. The development of a new vegetative shoot begins at the end of September during spring. The inflorescence begins to develop in October, along with the developing leaves, which culminate their development and flowering from November to the middle of December together with the fully developed leaves. The leaves remain until the end of January, sometimes February, and begin to dry, leaving the plant completely leafless in March-April and throughout the winter, between May and August, which are the months with the lowest temperatures, including below zero.

Etymology: —The new species is named in honor of Primavera Izaguirre who collected and recorded the species for the first time and for her contribution to the study of Uruguayan orchids.

Conservation Assessment: — Cyrtopodium izaguirreae is currently known from only two populations from the same region, about 50 km from each other ( Figure 3 View FIGURE 3 ). One of these populations with an estimated 500–700 individuals in an approximate area of 23,000 m 2 occurs in the protected area “Paisaje protegido Valle del Lunarejo”, in Rivera. The other population with an estimated 200–300 individuals in an approximate area of 1,500 m 2, is located in a private property, where overgrazing by livestock is its main threat. According to the IUCN Red List Categories and Criteria, and guidelines ( IUCN 2012, 2016), C. izaguirreae can tentatively be classified as Endangered (EN), due to its limited geographic range (EOO estimated in 19 km 2), small AOO estimated in 12 km 2, and two known populations [B1ab(iii)+2ab(iii)].

Additional specimens examined (Paratypes): — URUGUAY. Rivera: Bajada de Pena, en ladera arenosa, al sol, 24 Nov 1992 (fl.), P. Izaguirre et al. s.n. (MVFA 21463!); ibidem, 22 Dec 1992 (fr.), D. Baycé et al. s.n. (MVFA 21589!); Ladera superior norte, cerro Miriñaque, Cuchilla de los Tres Cerros, 20 Nov 2022 (fl.), A. González, J.L. Antúnez, M.H. Rosales & M. Gariglio s.n. (MHNH 23502!).

Taxonomic discussion: — Cyrtopodium izaguirreae was first collected and recorded by Primavera Izaguirre (2010), which presented an illustration, description and comments of the species, identified as C. brandonianum . This identification was followed by Pérez et al. (2020) in their commented list of Uruguayan orchids. A line drawing and a color photograph of the species were published by Izaguirre (2010, Figure 1A View FIGURE 1 ) and Pérez et al. (2020, Figure 4A View FIGURE 4 ), respectively, both as C. brandonianum . The predominantly pinkish flowers resembles C. brandonianum ( Figure 4A–D View FIGURE 4 ), as well as C. pallidum ( Figure 4I–L View FIGURE 4 ) and C. brandonianum subsp. lageanum ( Figure 4E–H View FIGURE 4 ), but the new species is in fact similar in terms of both vegetative and floral morphology to C. klenii ( Figure 4M–P View FIGURE 4 ), restricted to southern Brazil and Uruguay ( Figure 3 View FIGURE 3 ). The main differences between the two species are the color of the flowers and the morphology of the lip. In C. izaguirreae ( Figure 2 View FIGURE 2 ) the lip is pinkish (vs. midlobe yellow and lateral lobes red in C. klenii [ Figs. 4N, O View FIGURE 4 ]), the midlobe larger than the lateral lobes (vs. about the same size), lateral lobes 7–8 × 2–2.5 mm, longer than wide (vs. 3–4 × (2.5–)3–3.5(–4) mm, approximately of equal length and width in C. klenii [ Figure 4P View FIGURE 4 ]), and base of median lobe constricted (vs. with little or no constriction in C. klenii [ Figure 4P View FIGURE 4 ]) ( Table 1 View TABLE 1 ). A rather unusual feature of C. izaguirreae is the lip base and unguicule adaxially slight pubescenct, a feature we do not know in any other Cyrtopodium species.

Cyrtopodium izaguirreae ( Figure 2 View FIGURE 2 ) differs from C. brandonianum ( Figure 4A–D View FIGURE 4 ) in the size and morphology of the flowers. In C. izaguirreae the flowers are smaller, the base of the lip and the unguiculus are genuflexed, so that the connection of the lip with the foot of the column forms an angle of 180 o (vs. straight and forming an angle of 90 o in C. brandonianum ), and the leaves are shorter and wider among other differences ( Table 1 View TABLE 1 ). Cyrtopodium izaguirreae is also similar to C. lageanum ( Figure 4E–H View FIGURE 4 ), but differs in smaller flowers and well-developed leaves during flowering ( Table 1 View TABLE 1 ). Cyrtopodium izaguirreae may also be confused with C. pallidum ( Figure 4I–L View FIGURE 4 ) due to the color and size of the flowers, but it differs from this species by the smaller width between apex of the lip lateral lobes when spread, lip lateral lobes narrower, oblong ( Table 1 View TABLE 1 ) and parallel to each other ( Figure 2E View FIGURE 2 ), vs. dolabriform and divergent from each other ( Figure 4J–L View FIGURE 4 ).