To analyse the distribution ranges of the Pitcairnia species, a dataset of geographic distributions, based on specimens of all sampled species, was manually compiled in Microsoft Excel using herbarium records and online data available through the biodiversity portals Jabot (2024), Reflora (2024) and speciesLink (2024). Collections deposited in the BHCB, CEN, ESA, HB, HERBAM, HSTM, HUAM, HURB, IAN, IBGE, INPA, K, MBM, MG, MO, NY, R, RB, RO, RON, UFACPZ, US and V Herbaria (Thiers 2024) were consulted either in person or online.

Distribution points were carefully curated and only specimens identified or reviewed by taxonomists of the group were considered. Duplicates were excluded and only specimens analysed in person or through digitised images were included. Specimens without original coordinates were not added to avoid errors in location. For accuracy, locality data from specimen labels were cleaned to remove extraneous information such as habitat descriptions. Only the relevant locality details were included in the dataset. When specific locality information was essential, it was explicitly detailed in the text or table (Table 1). When necessary, points of occurrence were inferred, based on locations and verified using Google Earth (2024). These inferences were made in specific cases, particularly when only type material was available or when the coordinates of the material were relevant for discussions to be visualised on the map (e.g. Pitcairnia anomala, P. corallina, P. geyskesii, P. kirkbridei and P. sastrei). Distribution outlier records ("taxonomic suspicious") and specimens with coordinates matching the centroid of municipalities were considered inaccurate and deleted. Our final dataset contains 211 occurrence points (Carvalho 2024), which were filtered from 721 initially acquired points. The maps were created using QGIS (Quantum GIS Development Team 2023) by plotting the collection localities on a Neotropical base map from Hijmans et al. (2004) and the Amazon Rainforest base map from IBGE (2004).

Information about endemism, substrate, vegetation type and occurrence in federative units was taken from Flora e Funga do Brasil (Saraiva et al. 2024) and confirmed, based on the material examined. For species that are not endemic to Brazil, the occurrence information follows Tropicos.org (Missouri Botanical Garden 2024).

The geographic coverage encompasses eight States in the Brazilian Amazon, including Acre, Amapá, Amazonas, Mato Grosso, Pará, Rondônia, Roraima and Tocantins (Fig. 2).

Figure 1.  

Pitcairnia species that inhabit the Brazilian Amazon. a P. burchelli Mez; b-c P. patentiflora L.B.Sm.; d P. rubiginosa Baker; e P. sprucei Baker; f P. uaupensis Baker. Photos by B.M. Carvalho (d, e), D.P. Saraiva (a, f) and T. Bochorny & G. Marcusso (b, c).

Figure 2.  

Overview of geographical distribution of Pitcairnia (Bromeliaceae) in the Brazilian Amazon.

We recorded the occurrence of 24 species of Pitcairnia in the Brazilian Amazon, which are the following: P. anomala Hoehne, P. aureobrunnea Rauh, P. burchellii Mez, P. caricifolia Mart. ex Schult. & Schult.f., P. corallina Linden & André, P. crinita E.Pereira & Martinelli, P. frequens L.B.Sm. & B.Holst ex Saraiva & Forzza, P. geyskesii L.B.Sm., P. kirkbridei L.B.Sm. & Read, P. leprieurii Baker, P. maidifolia (C.Morren) Decne. ex Planch., P. neeana (L.B.Sm. ex H.Luther) J.R.Grant, P. patentiflora L.B.Sm., P. poeppigiana Mez, P. pulverulenta Ruiz & Pav., P. rondonicola L.B.Sm. & Read, P. rubiginosa Baker, P. sastrei L.B.Sm. & Read, P. semijuncta Baker, P. sprucei Baker, P. torresiana L.B.Sm., P. uaupensis Baker, Pitcairnia sp. nov. 1 and Pitcairnia sp. nov. 2 (Fig. 1; Table 1).

The Bromeliaceae monograph by Smith and Downs (1974) identifies 13 species of Pitcairnia in the Brazilian Amazon. However, the Flora e Funga do Brasil by Saraiva et al. (2024) reports a significantly higher number for the region (23 spp.). Based on our analysis, we confirmed the occurrence of the species listed by Flora e Funga do Brasil (Saraiva et al. 2024), one species was synonymised, one species was recorded for the first time for the Brazilian Amazon (P. aureobrunnea) and two new species were discovered and are in the process of being described. To date, this is the highest number of species recorded for the genus in the Amazon Region of Brazil (Fig. 2).

Amongst these species, nine are endemic to Brazil, of which seven exclusively occur in the Amazon domain (P. anomala, P. crinita, P. frequens, P. neeana, P. rondonicola, Pitcairnia sp. 1 and Pitcairnia sp. 2) and two (P. burchellii and P. torresiana) have a stronger association with the Cerrado domain (Table 1). Pitcairnia burchellii stands out as one of the species in the genus with the widest distribution in Brazil, where it occurs in states in the Northern, North-eastern, Central-Western and South-eastern regions (Saraiva et al. 2024).

The most well-documented species are P. burchellii, P. caricifolia, P. patentiflora, P. sprucei and P. uaupensis, which are widely distributed throughout the Amazon Basin (Fig. 3: a, b, c and d), occur on a greater diversity of substrates and, in many cases, are in accessible areas, such as anthropogenic zones and along river margins (Table 1). Conversely, many of the species have a low number of records and, in some cases, are only represented by a single collection (P. rondonicola and Pitcairnia sp. 2) (Table 1). This may be associated with the issues highlighted by Cardoso et al. (2017) and Hopkins (2019), which concern the difficulty of accessing areas and a lack of investment in basic research in the Amazon Region, resulting in undersampled areas. Furthermore, some of these species have records in areas that currently have high anthropogenic activity, which may have led to habitat loss, especially for those with only one record in the Amazon Basin (Table 1).

Figure 3.  

Pitcairnia in the Brazilian Amazon: geographical distribution for each species, based on georeferenced herbarium filtered data. a Pitcairnia sp. 1, P. semijuncta, P. sprucei and P. pulverulenta; b Pitcairnia sp. 2, P. anomala, P. caricifolia and P. uaupensis; c P. aureobrunnea, P. burchellii, P. kirkbridei and P. sastrei; d P. geyskesii, P. neeana, P. patentiflora, P. rondonicola and P. torresiana; e P. crinita, P. frequens, P. maidifolia and P. poeppigiana; f P. corallina, P. leprieurii and P. rubiginosa.

Most species can be found as rupicolous (19 spp.); eight are exclusively rupicolous, eight are both rupicolous and terrestrial and three are rupicolous, terrestrial and epiphytic. Five are exclusively terrestrial and none is exclusively epiphytic. The significant influence of rivers on the distribution of these species is evident (Fig. 2), considering that 17 species were recorded in forests associated with rivers and other watercourses (Table 1). Unlike many Amazonian groups, whose distribution patterns are often shaped by collection gaps (Stropp et al. 2020, Gomes‐da‐Silva and Forzza 2021), the unique distribution pattern of these species appears to stem from intrinsic biological and ecological characteristicsis.

This strong association with rivers and watercourses underscores the potential role of these habitats in shaping the distribution and diversification of these species. Similar patterns are observed in the Atlantic Forest and Cerrado, where numerous species exhibit a well-defined distribution pattern that is strongly linked with watercourses (Saraiva et al. 2015). This pattern suggests that the strong association of these species with these environments in the Amazon may result from multiple colonisation events over time, as Saraiva et al. (2015) noted, with Pitcairnia repeatedly occupying the Amazon Basin, Cerrado and Atlantic Forest through different evolutionary routes. These repeated colonisations likely drove convergent adaptations to these environments, leading to the formation of distinct geographic groups shaped by the unique ecological characteristics of these regions.

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