Cuba is a remarkably rich source of diversity of the genus Pinguicula L., considering it is an island with an area of only 110,860 km². The distribution of the genus Pinguicula in Cuba shows a disjunction over three regions – west, central, and east – with significant gaps between the regions. Of the 14 Cuban species currently accepted (Panfet 2024), nine occur within the eastern region. Before the middle to late 1960s, only five species had been recorded for the entire country: Pinguicula albida C.Wright ex Griseb., P. benedicta Barnhart, P. filifolia C.Wright ex Griseb., P. jackii Barnhart, and P. lignicola Barnhart (Alain 1957; Ernst 1961; Casper 1966). This changed from 1966 onwards when botanical expeditions were organised in Cuba as part of the work, Flora de la República de Cuba (Méndez 1995; Regalado Gabancho et al. 2008), which yielded numerous observations and collections of Pinguicula, including several new species. The resulting specimens are kept at the Herbarium Prof. Johannes Bisse (HAJB, National Botanic Garden of Cuba, University of Havana) with duplicates in German herbaria (B, Botanic Garden and Botanical Museum Berlin-Dahlem and JE, Friedrich-Schiller-Universität Herbarium Haussknecht).

During this period of botanical field trips, the identities of some specimens of white-flowering Pinguicula from the eastern region of Cuba remained undetermined (HFC-21959a, Ebel s.n. [HAL 36587], HFC-39913) but several were mistakenly identified as P. albida (HFC-16747, HFC-16918, HFC-21649a, HFC-21649b, HFC-21959b, HFC-21959c, HFC-56240b, HFC-56240c). This taxon was previously and correctly only known from the west of Cuba. At that time, only three white-flowered taxa were known, P. albida, the epiphytic P. lignicola, and some populations of P. filifolia, the latter two could not be confused with other Cuban Pinguicula species because of their distinctly unique morphological differences. Likewise, eastern Pinguicula with non-white flowers were commonly determined to be P. benedicta (HFC-56240a) based on superficial similarity.

Bisse et al. (1975) discussed an eastern Pinguicula identified as P. albida (HFC-16747) and outlined several differences between these plants, collected at Cayo Fortuna (located on the River Toa), and the more typically western populations but dismissed their importance. Thus, despite an early indication by F. Ebel in 1972 that another specimen from Cayo Fortuna (Ebel s.n. [HAL 37587], in sched.) was a new species, the view was maintained that P. albida was not restricted to western Cuba.

Fortunately, the late Siegfried Jost Casper recognised that many of the herbarium specimens from eastern Cuba were new taxa. His descriptions (Casper 2003, 2004, 2007, 2019) allowed a better comparison between the species, especially those from the east that were significantly less well known. Among these new species was the white-flowered Pinguicula jaraguana Casper (Casper 2003), of which the type material (HFC-39913) was collected beside a stream, the Arroyo Jaragua, within the Alejandro de Humboldt National Park, where it is generally found growing on vertical wet walls in shaded locations. As a result of separating eastern white-flowered species into P. jaraguana, thereafter, P. albida was considered endemic to western Cuba and all white flowering species from eastern Cuba were considered to be P. jaraguana. However, Casper was unaware of a number of specimens from separate gatherings from Cayo Fortuna, a region within the Ojito de Agua sector of the same park. Therefore, these specimens remained uncited and without proper determination. Later, Casper (2019) published a revision of the genus in the Greater Antilles and included the Cayo Fortuna specimens within his concept of P. jaraguana. He noted that there are differences in flower morphology between the plants from the P. jaraguana locus classicus beside the Arroyo Jaragua and those from Cayo Fortuna. Despite these differences, he concluded that the observed differences were within the range of variation of P. jaraguana. Thus, all Cayo Fortuna collections were subsumed under P. jaraguana. By 2007, the early F. Ebel gathering (Ebel s.n. [HAL 36587]), originally determined as “Pinguicula nov. spec.”, had captured Casper’s attention and he newly determined it as “Pinguicula c.f. jaraguana”. Later still, this specimen, as well as a colour photograph of living plants in habitat also supplied by F. Ebel, was cited by Casper (2019); his explicit mention of the Cayo Fortuna population, where he used those plants as a comparison of P. jaraguana with P. albida, demonstrated his inclusion of the population within P. jaraguana. By this time, other specimens from Cayo Fortuna were also subsumed within P. jaraguana, likely because they lacked flowers (HFC-16747 and HFC-16981). However, our preliminary analyses of herbarium specimens revealed that, without exception, specimens from this locality do not represent the P. jaraguana species concept.

In recent years (2019–2025), several expeditions had been undertaken to study populations of eastern Cuba Pinguicula. Morphological analyses and field observations allowed the recognition of clear morphological and ecological differences between the population of Pinguicula from Cayo Fortuna and all other known white-flowered species these plants have been confused with. Thus, a new species of Pinguicula from eastern Cuba is herein described and illustrated. Its taxonomic relationships, distribution and ecology, and its preliminary conservation status are also presented.

Field trips were conducted between November 2019 and March 2025 to study Pinguicula populations in eastern Cuba. Plants from a single population previously attributed to P. jaraguana, located at Cayo Fortuna, (a section of the River Toa), were examined and compared with type material and specimens (Supplementary material 1) of Pinguicula albida and P. jaraguana from herbarium collections (A, B, BRU, GH, GOET, HAC, HAJB, HAL, HFA, HPPR, HUMC, JE, MA, MO, MT, NY, US, and YU; acronyms follow Thiers 2025). Collected material was also compared to descriptions in the relevant literature (Alain 1957; Ernst 1961; Casper 1966, 2003, 2004, 2007, 2019; Bisse et al. 1975; Domínguez et al. 2014; Temple et al. 2023).

Macro- and micromorphological analyses of recently collected specimens and older specimens in herbarium collections, as well as field observations, were carried out to describe the new taxon. Field photographs were taken using a Canon R6 Mark 2 camera with 100 mm f2.8 macro (Canon, Japan) or Laowa 25mm f2.8 2.5–5× ultra macro lens (Venus Optics, China). Micromorphological characters were analysed and photographed using a BEL microscope model SOLARIS-T with a coupled digital camera BEL EU 12 CONVS (Bel Photonics®, China) using the software Capture 2.1 (Meiji Techno, Japan). Eight quantitative vegetative and reproductive characters (Table 1; Supplementary material 2) were recorded for each taxon (n = 60). The normality of the data was assessed for each variable individually using the Shapiro-Wilk’s test (p values = 0.000–0.020; Supplementary material 3). To compare morphometric data, a multivariate analysis was performed to reduce dimensionality and obtain new axes that better explain data variation. A principal component analysis (PCA) based on the correlation matrix was performed, with the absolute values transformed to z-scores and plotted in a two-dimensional space defined by the first two principal components (Factor 1 and 2). All statistical analyses were performed using SYSTAT 13 v.13.2.01 (Systat Software, Inc. 2023).

The preliminary conservation status of the new species was assessed following IUCN Red List Categories and Criteria (IUCN 2024), for which the extent of occurrence (EOO) and the area of occupancy (AOO, with 2 × 2 km grid) were calculated using the software GeoCAT (Bachman et al. 2011). The distribution map, based on the known distribution of the species according to herbarium records and field surveys, was prepared with QGIS v.3.40.3 (QGIS Development Team 2024).

Morphological differences observed among the three species are useful to characterise and identify them (Fig. 4; Table 2) and showed consistency among the analysed individuals of each taxon. Furthermore, the results of the PCA revealed two principal components that together explain 81.86% of the total variation in the data (Factor 1: 68.13%, eigenvalue 5.451; Factor 2: 17.73 %, eigenvalue 1.419; Fig. 5A; Table 3). Plotting z-scores of the individuals’ characters against the axes defined by Factors 1 and 2 also revealed three separated groups corresponding to the sampled individuals of each species, with no overlap in their morphospaces (Fig. 5B). Factor 1 was defined by reproductive characters with high positive weight. This component separated species based on inflorescence scape length (SCL), flower length (FLL), and the length (LBL, MLL) and width (LBW, MLW) of the corolla lobes. Pinguicula jaraguana appears to the right end of the axis, showing longer inflorescences and larger flowers, followed by P. panfetiae, and finally P. albida, with shorter inflorescences and smaller corollas (Fig. 5B; Table 2). These reproductive traits have been highlighted as relevant characteristics to discriminate among related species of Pinguicula (Conti and Peruzzi 2006; Peruzzi and Gestri 2013; Domínguez et al. 2014; Burelo-Ramos et al. 2018; Crespo et al. 2020). On the other hand, Factor 2 was defined by leaf length (LFL) and width (LFW), both showing high positive weight (Fig. 5A) indicating the presence of smaller leaves in P. panfetiae; however, the overall variation of these vegetative characters is attributed to intraspecific variability (Fig. 5B). Moreover, qualitative vegetative characters, such as leaf growth, shape and margin, were also recognised as diagnostic characters useful to differentiate the three species (Fig. 4; Table 2), as previously noted for other groups of related taxa within Pinguicula (Casper et al. 2020; Crespo et al. 2020; Pérez et al. 2023). These traits may be associated with the specific environmental conditions in which each species thrives, including their adaptation to different light exposure and water availability.

The new species was discovered along the banks of the River Toa within the Alejandro de Humboldt National Park. This region is well-known for its high level of endemism, often associated with the presence of serpentine-derived soils, and has been highlighted as the main centre of diversification and endemism of the mountainous flora of Cuba (López Almirall 2013; López Almirall and Duarte 2022). Pinguicula panfetiae shares its habitat with P. jaraguana in ferritic soils derived from serpentine bedrocks (charrascales) in eastern Cuba; while P. albida occurrences include populations in serpentine derived soils in western Cuba (cuabales) (Fig. 4). According to Borhidi (1996), serpentinophilous floras of eastern and western Cuba resulted from intensive local speciation and represent independent evolutionary scenarios.

With the description of P. panfetiae, our findings confirm that Cuba is a hotspot for Pinguicula diversity, hosting at present 15 species and one subspecies, all of which are endemic to the Cuban archipelago. This diversity aligns with the concept of a Central American-Caribbean centre of diversity for the genus (Casper 2019) and reinforces the need for a more accurate assessment of the taxonomic diversity of the group in remote areas. Ten of the Cuban species are found exclusively in eastern Cuba, a region recognised as a centre of endemism for the genus (Domínguez et al. 2024). Although most Cuban species are distributed within conservation units, they remain exposed to threats due to the limited geographic ranges of known populations, particularly those species that are known from a single location, such as P. panfetiae. Furthermore, as for other species, the single population of P. panfetiae may be impacted by local and global climate changes, but no evidence of specific climate risks to this taxon has been obtained as yet.