Porroglossum hildeae M. F. Monteros, E. Restrepo & Baquero, 2025

Porroglossum hildeae M. F. Monteros, E. Restrepo & Baquero sp. nov.

Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3

Holotype.

Ecuador • Imbabura: Reserva Río Manduriacu, 11 July 2021 (coordinates omitted for conservation reasons; detailed data on the herbarium Type specimen), Marco F. Monteros, MFM 212 ( QCNE!).

Diagnosis.

Most similar to P. josei Luer but distinguished by the longer, narrowly obovate leaves 8.0–9.0 cm long (vs. shorter, elliptical, 4.5 cm long), tail length of the dorsal sepal 6 mm long (vs. 1.5 mm long), longer lateral sepaline tails 19–20 mm long (vs. ca. 14 mm), petals oblong-ovate with one acute angle near the middle of the upper margin (vs. ovate with two acute angles below the middle), obtrullate blade of the lip with an attenuate base (vs. obovate) and apex of the lip acute (vs. obtuse and abruptly acuminate).

Description.

Plant epiphytic, caespitose, up to 20.0 cm tall including the inflorescence. Roots slender, ca. 1.0 mm in diameter. Ramicauls erect, slender, ca. 2.0 cm long, enclosed by 2–3 tubular sheaths. Leaf erect, coriaceous, verrucose, long-petiolate, 8.8–9.2 cm including the petiole 3.3–3.7 cm long; the blade 4.6–5.7 × 0.9–1.2 cm, narrowly obovate, the apex obtuse, mucronate; the base narrowed into a slender, conduplicate petiole. Inflorescence borne at the apex of the ramicaul, with few-flowered, successive, congested coflorescences, one developing at a time, erect to suberect, with slowly successive flowers, 1 opened at a time, up to 27.0 cm long, including the slender, glabrous pseudopeduncle 17.0– 24.5 cm long, with 3–4 internodes, with a few widely spaced thin translucent bracts. Floral bracts tubular, imbricating, 7.0–10.0 mm long; pedicel 10.0– 11.6 mm long. Ovary glabrous, sulcate, minutely foveolate, 4.0 mm long. Flowers resupinate with a strong vanilla and clove fragrance in the early evening. Sepals bright orange-yellow, hyaline, commonly with red veins. Dorsal sepal reniform, 3 - veined, 5.0–7.0 × 17.0–20.0 mm when expanded, connate to the lateral sepals for 3 mm to form a gaping cup, the apex acutely reflexed, abruptly contracted into a tail ca. 6.0 mm long. Lateral sepals ovate, oblique, 3 - veined, 6.0–7.0 × 9.0–10.0 mm, connate 5 mm to form an acute mentum below the column-foot; the apex oblique, acute, contracted into a slender tail, 19.0–20.0 mm long. Petals bright yellow with an orange-colored midvein, oblong-ovate, 4 × 2 mm, narrowed to the slightly, clawed, rounded apex, the upper margin with an acute angle near the middle. Lip bright orange-yellow, with dark, brown-red that extends from the apex toward the apical third of the callus gradually degrading into very small spots at the base of the callus, the blade shortly pubescent toward the apex, obtrullate, 7.4 × 4.1 mm, sensitive and actively motile, the thickened callus with a shortly elevated keel running longitudinally towards the base; the apex attenuate, acute, with a sulcus running 1.5 mm from the apex to the center of the blade; the base deflexed and hinged to the free apex of the column-foot by a strap-like claw. Column greenish-cream, stout, semi-terete, 3 mm long, with tooth-like processes near the stigma, the column-foot slender, curved, 6 mm long. Pollinia 2, greenish-yellow, obovate, each with a glandular caudicle, 1 mm long. Fruits and seeds not seen.

Paratype.

Ecuador • Imbabura: Reserva Río Manduriacu, 19 February 2024 (Coordinates omitted for conservation purposes; detailed data in the herbarium specimen), Marco F. Monteros, MFM 312 ( Paratype: QCNE!) .

Eponymy.

The specific epithet is a noun in the genitive case, honoring Hildegarden Toeppfer de Kohn (1912–2006), a Czech refugee who settled in Ecuador in 1945. A devoted admirer of nature, particularly orchids, she inspired in her children and grandchildren a deep appreciation for the natural world. This legacy ultimately led them to establish the Río Manduriacu Reserve, the site where this species was discovered.

Phenology and flower variations.

Flowering individuals of Porroglossum hildeae have been observed in January, March, and November. During these periods, four plants were recorded in bloom, while six others remained non-flowering. The flowers exhibit variation in size and in the coloration of the veins on the dorsal and lateral sepals, ranging from dark brown, particularly on the adaxial surface of the apical sepal, to complete absence.

Distribution, habitat, and ecology.

Porroglossum hildeae is so far restricted to two nearby locations within the Río Manduriacu Reserve in northwestern Ecuador, where it grows as an epiphyte at 1,600 m a. s. l. The habitat of the new species corresponds to a lower montane forest of the western Andes (BSN 04), which is a humid ecosystem with high biodiversity located between 1,000 and 2,000 m a. s. l., under conditions of high cloud cover, and annual rainfall exceeding 2,000 mm (Fig. 4 View Figure 4 ). It has a high coverage of medium and large trees, with abundant presence of epiphytes, mosses, tree ferns, and lianas (Ministerio de Ambiente de Ecuador 2013). It is a habitat for numerous endemic and threatened species, particularly orchids, birds, and amphibians, and plays a key role in water regulation in the Guayllabamba Basin in northwestern Ecuador ( Roy et al. 2018; Baquero and Galarza-Verkovitch 2019; Guayasamin et al. 2019; Brito et al. 2020; Reyes-Puig et al. 2020; Monteros et al. 2022; Monteros et al. 2023). The newly described taxon grows sympatrically with other Pleurothallidinae species such as Lepanthes kuijtii Luer & Hirtz , L. magnifica Luer , L. hexapus Luer & R. Escobar , Pleurothallis cauda-phocae Luer & Hirtz , Masdevallia nidifica Rchb. f. , M. purocafeana M. F. Monteros & Baquero , Dracula erythrocodon Luer & Dalström , and Scaphosepalum dodsoni Luer.

Preliminary conservation status

The newly described taxon is restricted to a single locality in northwestern Ecuador, with an extremely limited AOO, estimated at 4 km 2, and is subject to intense and ongoing pressures, including deforestation and mining activities ( Roy et al. 2018). The expansion of extractive industries and agricultural frontiers in northwestern Ecuador, combined with degradation of habitat quality, increases the risk of extinction (Fig. 5 View Figure 5 ). Given these factors, we recommend that P. hildeae be classified as Critically Endangered ( CR B 2 ab (iii, v )) according to the IUCN Red List Categories and Criteria ( IUCN 2022), due to its restricted distribution, ongoing habitat loss, overexploitation, and potential mining activities in the region.

Taxonomic comments

A group of species of Porroglossum are known for having a considerably wider dorsal sepal compared to the lateral sepals, including P. actrix Luer & R. Escobar , P. amethystinum (Rchb. f.) Garay , P. nutibara Luer & R. Escobar , P. aureum Luer , P. rodrigoi H. R. Sweet , P. hoeijerii Luer , P. marniae Luer , P. raoorum Baquero & Iturralde , and P. josei , which was known to have the widest dorsal sepal in the genus ( Baquero and Iturralde 2017) (Fig. 3 View Figure 3 ). Nevertheless, with the discovery of P. hildeae , another species with an extremely wide dorsal sepal is added to the genus. Although the main differences between both species were outlined in the diagnosis, a few more morphological differences are discussed here: the new species can be distinguished from P. josei by the considerably larger plants (up to 20.0 cm including the inflorescence vs. up to 10 cm), the longer leaves (reaching 9.0 cm in length vs. up to 4.5 cm long), the wider, reniform, 5.0–7.0 × 17.0–20.0 mm dorsal sepal (vs. transversely ovate, 8.0 × 17.0 mm), the longer tails of the dorsal and lateral sepals (6.0 mm and 19.0–20.0 mm long respectively vs. 1.5 mm and 14.0 mm long), the oblong-ovate petals with slightly clawed apex with a single acute angle below the middle (vs. petals with subclavate apex and both margins sharply angled on both sides below the middle), the lip blade obtrullate, attenuate, acute, shortly pubescent towards the apex, (vs. glabrous, widely obovate, broadly obtuse, acuminate) (Figs 1 View Figure 1 , 2 View Figure 2 , 3 View Figure 3 ).

Porroglossum hildeae is restricted to the southern sector of the Cordillera del Toisán (Guayllabamba River Basin), while the most similar species, P. josei , occurs north of the range in the Mira River Basin. This geographic disjunction suggests allopatric isolation mediated by the Cordillera del Toisán as a biogeographic barrier. Similar patterns have been documented in Pristimantis frogs ( Reyes-Puig et al 2022; Yánez-Muñoz et al. 2025) and in the genus Teagueia ( Jost 2004) , where watershed isolation and microvicariance drive lineage diversification. These comparisons highlight Andean orogeny and topographic heterogeneity as recurrent drivers of speciation in the Tropical Andes ( Reyes-Puig et al 2022; Jost 2004; Yánez-Muñoz et al. 2024; Yánez-Muñoz et al. 2025). In this context, the potential isolation of P. hildeae and P. josei provides additional evidence of these processes, though integrative morphological, genetic, and ecological studies remain necessary to confirm their evolutionary histories and independence.