Habenaria granitica Lozano-Cif., J.E.Ríos & J.A.N.Bat., 2025

Habenaria granitica Lozano-Cif., J.E.Ríos & J.A.N.Bat. , sp. nov.

( Figures 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Type: — COLOMBIA. Vichada: Municipality of Cumaribo, Cerro Ardilla o Humiento , 250 m, 5º49’16.24” N, 67º37’12.18” W, 12 July 2023 (fl.), D. Lozano-Cifuentes et al. 105 (holotype: TOLI barcode: 32480 !; GoogleMaps isotypes: BHCB, COL, JAUM, JBB) GoogleMaps .

Similar to H. dusenii in general floral morphology but distinguished by shorter pedicel (9.8–10.4 mm long vs. 15–28 mm long), shorter spur (21–26 mm long vs. 29–39 mm long), separate pollinaria (vs. joined by viscidium), and vegetative morphology, with patent and usually basal leaves (vs. distributed along the stem and adpressed to it).

Description: — Plant herbaceous, geophytic and saxicolous, up to 55 cm tall. Roots 1.1–1.3 mm wide, up to 5–7 cm long; tuberoid ca 2.5 × 1.3 cm, ellipsoid. Stem 33–53 cm long including the inflorescence, 2.5–5.0 mm wide, erect. Leaves 4–6 spirally-alternate, linear-lanceolate, spreading 4.5–10.0 × 0.5–1.2 cm, spaced 3–6 cm long, reducing in size towards the apex of the stem, sheathing at the base, apex acuminate. Inflorescence 6–14 cm long, spiral-alternate, 2.5–3 flowers/cm of the rachis; floral bracts 11.7–14.0 × 3–4 mm, green, ovate to lanceolate, apex acuminate. Flowers 1–3(– 6), resupinate, green with yellow, glabrous, pedicellate ovary 25–27.5 mm long, slightly curved to strongly curved, or ascending; ovary 14–17 × 1.1–1.5 mm, pedicel 9.8–10.4 mm long. Sepals green, margin smooth; dorsal sepal 5.0–7.0 × 4.0– 5.1 mm, concave, ovate when flattened, apex mucronate, lateral sepals slightly concave, deflexed, apex acute 7.0–8.5 × 3.8–4.0 mm. Corolla light green to yellowish. Petals bipartite, posterior segment (3.1–)4.0–5.0(–6.7) × 1.5–2.2 mm, falcate, narrowly triangular, apex acute, free from the dorsal sepal; anterior segment (9–)9.7–10.5(–11.4) × 0.4–0.6 mm, 2–2.3 times longer than the posterior segment, reflexed, inserted at the base of the posterior segment, filiform. Lip tripartite, undivided basal part 1.8–2.0 × 1.5–1.8 mm; lateral segments 11.3–12.2 × 0.65–0.7 mm, 1.3–1.4 times longer than the median segment, reflexed, filiform; median segment 8.2–9(–9.8) × (0.9–) 0.98–1.3 mm, curved backwards; spur (21.0–)24.1–25.7(–26.9) × 0.7–0.8 mm, 1.2–1.3 times longer than pedicellate ovary, deflexed, free from the bracts, parallel to the pedicellate ovary, green yellowish. Gynostemium erect, 1.6–1.9 mm high; connective retuse, long, 0.8–1.8 mm between the anther loculi, middle thickened, light green; lateral appendages (auricles) small, 0.4–0.6 × 0.3–0.4 mm, whitish. Anther bilocular, loculi parallel, 0.9–1.3 mm high, canals short, 0.3–0.4 mm long; hemi-pollinaria separate, viscidia 0.2 × 0.2 mm, spaced 0.5–0.8 mm from each other. Stigmatophores (stigma lobes) 2, closely parallel, 1.3–1.4 mm long, light green, receptive surface slightly convex, turned frontwards. Rostellum 1.3–1.4 mm long, whitish; mid-lobe triangular, fleshy, completely placed between the anther loci, 0.9 mm high; apex rounded to acute, curved frontwards; side-lobes sulcate, slightly convergent towards apices, 0.9 × 0.35 mm.

Distribution and ecology: — Habenaria granitica is currently known only from the Amazon and Orinoco regions, in the border between Venezuela and Colombia ( Figure 5 View FIGURE 5 ). The specimens were associated with Llanos, Rio Negro Campinarana and Negro-Branco Moist Forest ecoregions (sensu Olson et al. 2001). In Colombia, it is known from six populations in the Colombian Orinoquia in the department of Vichada, within the municipality of Cumaribo, including the Parque Nacional Natural El Tuparro. The new species is found exclusively in granite outcrops inhabiting saxicolous plant communities ( Figure 1 View FIGURE 1 ), specifically in depressions that form microhabitats colonized by lichens and mosses. The populations grow amidst shrubs of the genus Amanoa Aublet (1775: 256) , predominantly surrounded by individuals of Lindmania Mez (1896: 535) , Utricularia chiribiquetensis Fernández (1964: 42) , U. subulata Linnaeus (1753: 18) , and U. neottioides Saint-Hilaire & Girard (1838: 869) , as well as some lianas of the genus Ipomoea Linnaeus (1753: 159) ( Convolvulaceae ) and Mandevilla Lindley (1840: 7) ( Apocynaceae ). In Colombia, specimens were found flowering from June to July, coinciding with the intense rainy season; it should be noted that there were traces indicating that during the dry season, there are massive fires on the surface of the outcrops. In the Venezuelan Amazon , records indicate flowering from July to September, although there is one record of flowers in May.

Etymology: —From the Latim graniticus, of granite, referring to the granite outcrops where the species occurs.

Conservation status: — Habenaria granitica is so far known from six collections from six localities from the Amazon and Orinoco regions of Colombia and Venezuela ( Figure 5 View FIGURE 5 ) and shows an EOO estimated at 20,833 km 2 and an AOO of 40 km 2. In Colombia, it is known from five populations on the periphery of El Tuparro National Natural Park and one population within the park. In each of these populations, approximately 15–40 flowering specimens were observed. Some of the records for Venezuela indicate that the species is locally frequent. In Venezuela, one of the records is from Yapacana National Park and another from Alto Orinoco-Casiquiare Biosphere Reserve. The new species is restricted to the bordering regions of Colombia and Venezuela in the Escudo Guayanés, one of the few areas that promote special ecological conditions to generate ecosystems that allow speciation and endemism in the Llanos Colombo-Venezolanos ( Gentry 1981, Figueredo et al. 2014, Aymard 2017). This area is under pressure and increasing threats from the expansion of the agro-industrial frontier, timber exploitation and hydrocarbon extraction ( Veillon 1976, Pacheco-Angulo et al. 2011a, b, 2012, 2013, 2017, Aymard & Vélez-C. 2015, Guevara 2015, Aymard 2017). Based on the above observations, the small AOO and the IUCN Red List Categories and Criteria ( IUCN 2020), the species can be tentatively classified as Endangered: EN 2ab(iii); C2a(i).

Illustrations: — Foldats (1969, figure 14, as H. dusenii Schlechter [1919: 251] ), most likely based on Wurdack & Adderley 43521, reproduced in Szlachetko et al. (2017, figure 246, as Rhinorchis dusenii (Schltr.) Szlachetko [2012: 74] ).

Additional specimens examined (paratypes): — COLOMBIA. Vichada, municipio de Cumaribo, PNN El Tuparro , Cerro Carestía , 120 m, 25 July 2009 (fl.), L. Clavijo et al. 1436 ( COL [barcode: 000432030 !]) . VENEZUELA. Amazonas, on right bank of Río Siapa , 8 km below Raudal Gallineta (about 110 river km. from mouth), 130–300 m, 20 July 1959 (fl.), J.J. Wurdack & L.S. Adderley 43521 ( AMES [barcode: 01947840 !], G!, NY [barcode: 04094396 !], U [barcode: 1459680 !], US) ; Amazonas, Atabapo, 44 km al NW de San A. del Orinoco , 3 o 30’N, 67 o 17’W, 130 m, sabana con arbustos en grupos o esparcidos, planicie arenosa y anegadiza, flores verde claro en zona húmeda, May 1990 (fl.), E. Marin 1281 ( MO [barcode: 04946671 !]) GoogleMaps ; Amazonas, Alto Rio Orinoco, savannas at northwest base of Cerro Yapacana , 125 m, occasional, flowers yellow-green, 16 September 1957 (fl.), B. Maguire et al. 41523 ( AMES [barcode: 00099934 !], NY [barcode: 00073812 !]) ; Amazonas, Atures, Tobogán de la Selva , Río Coromoto , 35 km SE of Puerto Ayacucho, among igneous exposures, 5 o 27’N, 67 o 33’W, 80 m, on laja, flowers green, spur pale yellow, base of orifice dark purple, 7 September 1985 (fl.), J.A. Steyermark et al. 131583 ( MO [barcode: 3291048 !]) GoogleMaps .

Taxonomic discussion: —As far as we could find, H. granitica was first collected by Basset Maguire in 1957, in savannas at northwest base of Cerro Yapacana, in the Upper Orinoco River, Venezuela. This record was identified by Schweinfurth (1967) as H. macilenta ( Lindley 1843: 673) Reichenbach (1865: 180) , who pointed out some differences between this collection and the type material. Accordingly, on the specimen Maguire et al. 41523 (AMES), there is an identification tag with the name H. macilenta var. longiloba Schweinfurth ( Figure 4B View FIGURE 4 ), but this name was never published. Romero-González was the first taxonomist to recognize that it was a new species, and in the specimen Clavijo et al. 1436 (COL) there is a 2009 annotation identifying it as such ( Figure 4D View FIGURE 4 ). At the time, this issue was discussed with one of the authors (JANB), but the description of the species ended up not going forward.

Habenaria granitica differs from H. macilenta by smaller flowers (dorsal sepal 5.0–7.0 mm long vs. 10–12 mm long), shorter pedicel (9.8–10.4 mm long vs. 17–32 mm long), rostellum midlobe triangular (vs. galeate) and separate pollinaria (vs. united through the viscidium or with the viscidia remarkably close to each other). Habenaria macilenta is morphologically similar to species of H. sect. Spathaceae Kränzlin (1892: 94), which includes H. trifida Kunth (1816: 330) , one of the most widely distributed species in the Neotropics ( Batista et al. 2011b). However, it is phylogenetically related to a clade that includes H. sect. Sartores Kränzlin (1892: 94), H. sect. Pentadactylae Kränzlin (1892: 114), H. regnellii Cogniaux (1893: 60) and H. repens Nuttall (1818: 190) , taxa with which it has no apparent morphological similarities ( Batista et al. 2013).

Other records of H. granitica were mistakenly identified as H.dusenii by Schweinfurth (1967) and this identification was followed by all subsequent authors ( Figure 4C View FIGURE 4 ). Although the general floral morphology is somewhat similar between the two species, H. granitica differs by the patent leaves generally concentrated in the lower part of the stem (vs. adpressed to the stem and distributed along it), shorter pedicel (9.8–10.4 mm long vs. 15–28 mm long), shorter spur (21–26 mm long vs. 29–39 mm long), and column morphology, with separate pollinaria (vs. united in H. dusenii ) ( Figures 2–3 View FIGURE 2 View FIGURE 3 ). Additionally, H. granitica occurs in granite outcrops (vs. wet grasslands with hydromorphic soil) and is restricted to the Amazon and Orinoco regions of Colombia and Venezuela, while H. dusenii is widely distributed in central, southeastern and southern Brazil. Habenaria sylvicultrix Lindl. ex Kränzlin (1892: 101) , from the Brazilian Amazon, is similar and possibly conspecific with H. dusenii ( Batista et al. 2011a) . If this assumption proves to be true the distribution of H. dusenii also includes northern Brazil, however this issue is still unclear. A comparative table with diagnostic characters for Habenaria granitica and these morphologically similar or previously misidentified species is presented in Table 1 View TABLE 1 .

Habenaria dusenii is morphologically and phylogenetically related to a group of species characterized by mediansized flowers (dorsal sepal 4–7 mm long), elongated pedicel, generally longer than the ovary, spur approximately the same length as the pedicellate ovary and by pollinaria united by viscidia, which includes, among others, H. longipedicellata Hoehne (1937: 133) , H. rodeiensis Barbosa Rodrigues (1882: 256) , H. ernestii Schlechter (1914: 122) and H. lehmanniana Kränzlin (1892: 97) . Since H. granitica does not share any of these characteristics, it does not appear to be related to H. dusenii . Based on morphology alone we were unable to associate H. granitica with any of the major Neotropical Habenaria clades ( Batista et al. 2013), and the phylogenetic relationships of the new species will depend on obtaining suitable material for molecular phylogenetic analyses.

The specimens Maguire et al. 41523 (AMES) ( Figure 4B View FIGURE 4 ) and Marin 1281 (MO) have slightly wider leaves than the other specimens of the species we examined. However, since the floral morphology and area of occurrence are the same as other specimens of H. granitica , we consider these differences as a variation of the species. The specimen Steyermark et al. 131583 (MO) does not have good flowers left, but since the vegetative morphology, floral remains, flower color, area of occurrence, habitat and flowering time agree with H. granitica , we tentatively assign it to that species. The only specimen in the holotype of H. granitica ( Figure 4A View FIGURE 4 ) has leaves distributed along the stem and is taller than most other specimens of the species we examined ( Figures 4B–D View FIGURE 4 ). The growth and length of the stem in Habenaria depends on the surrounding vegetation and the amount of light the plants receive. Plants growing in more open areas and more exposed to the sun are generally shorter, while plants growing in more enclosed areas and more protected from the sun are generally more elongated or etiolated (J.A.N. Batista, pers. comm.). This is probably the case in the type specimen.

Habenaria granitica has gone unnoticed in most studies on Venezuelan and Colombian orchids. The species appears in the Flora de Venezuela ( Foldats 1969) as H. dusenii , based on the collection Wurdack & Adderley 43521 (AMES, G, NY, U, US) ( Figure 4C View FIGURE 4 ). However, it is not among those illustrated for Venezuela in Dunsterville & Garay (1959 – 1972, 1979) or among the species recorded for Colombia by Szlachetko et al. (2017). In the Flora of the Venezuelan Guayana ( Foldats et al. 2003) the authors comment that the illustration of H. dusenii in Foldats’ Flora de Venezuela (figure 14, page 56) is a composite of a plant similar to H. leprieurii Reichenbach (1846: 376) and idealized flowers of H. dusenii based on the original description and illustration of this species. However, this observation is mistaken, since the illustrated plant is not similar to H. leprieurii and matches well with H. granitica and with the specimens in the Wurdack & Adderley 43521 collection, the only material cited for the species, and most likely on which the illustration is based.

Granite outcrops or inselbergs constitute spatially isolated habitats surrounded by forests or savannas. In Southern Venezuela, the orchid flora of the granite outcrops, locally known as lajas, is composed of a small number of endemic species and a large component of species from the surrounding forest or savanna ( Romero-González 1993). Orchid species endemic to these habitats are invariably associated to the granite outcrops and include Cyrtopodium graniticum G.A.Romero & Carnevali in Romero-González (1999: 512), Acianthera granitica Luer & G.A.Romero in Romero-González & Fernández-Concha (2000: 1142) Luer (2004: 253), Sobralia granitica G.A.Romero & Carnevali in Romero- González et al. (2000: 184) and Catasetum bergoldianum Foldats (1968: 318) . The discovery and description of Habenaria granitica adds yet another species endemic to these unique habitats.