This data paper describes a specimens’ dataset of the Catalonian threatened vascular plants conserved in five public Catalonian herbaria (BC, BCN, HGI, HBIL and MTTE). Catalonia is an administrative region of Spain that includes large autochthon plants diversity and 199 taxa with IUCN threatened categories (EX, EW, RE, CR, EN and VU). This dataset includes 1,618 records collected from 17^th century to nowadays. For each specimen, the species name, locality indication, collection date, collector, ecology and revision label are recorded. More than 94% of the taxa are represented in the herbaria, which evidence the paper of the botanical collections as an essential source of occurrence data.

Catalonia, conservation, Cormophyta , herbarium, northeastern Iberian Peninsula, specimen, threatened flora

For the maintenance of ecosystem processes, effective conservation is essential (Rands et al. 2010) and natural history collections have been recognized as a valuable source of data for applied these conservation efforts (Krupnick et al. 2009) due they are permanent and well-documented distribution records of taxa through time and space. There are many studies that show how the specimens stored in herbaria are useful for better knowledge of endangered flora; for instance, to evaluate the impact of over-collecting in the past for nowadays extinct plants (Aedo et al. 2015), to prioritize regionally rare plants for conservation (Kricsfalusy and Trevisan 2014) or to evaluate threatened flora hotspots (Mendoza-Férnandez et al. 2015). But not only the primary data included in the label is useful for biodiversity studies, Greve et al. (2016) shows how other information related to the specimen’s environment can provide distribution maps of soils types or vegetation; and Calinger et al. (2013) demonstrate changes on the flowering phenology due to climate change from the visual examination of the specimen’s flowers.

The searching of endangered plants in the herbaria allowed us to find 1,618 specimens from Catalonia. Although in these herbaria there are also many specimens collected in other Spanish regions or other countries, we have only recorded those collected in Catalonia. Table 1 shows the number of taxa and the specimens founded for each IUCN categories. More than 94% of the 199 taxa are represented in the herbaria, which evidences the paper of the botanical collections as an essential source of occurrence data. Only the regionally extinct taxa (RE) are less present in the herbaria due to the old bibliographic cites without voucher specimens. However, the 96.70% of the endangered taxa (VU, EN and CR) have almost one specimen, which demonstrates the good representativeness of this dataset per this kind of flora.

Table 2 shows the number of taxa according to the number of specimens stored in the herbaria and the IUCN category. The taxa with more than 30 specimens only represent the 4.26% of all the taxa included in the dataset, while more than 50% of the taxa have a few number of them (20 taxa only with a single specimen). We can see a general trend of the number of taxa decline as the number of specimens increases (from left to right of the table), and another general trend of the number of specimens decline as the threat degree increases (from top to down of the table), already observed in Nualart et al. (2012). These trends evidence that taxa with lower risk of extinction are more collected than the more endangered ones. This fact is due because usually these last taxa are infrequent, often with a small population size, a restricted and/or fragmented distribution area and come from difficult access habitats. Furthermore, many of these taxa have some type of protection that prohibits their gathering according to the Catalogue of Endangered Flora (DOGC 2008; 2015). These characteristics could explain the difficulty in their gathering and therefore, their small number of specimens.

Figure 2 shows the herbarium origin of all the specimens included in this dataset and as it is expected, the number of specimens is proportional to the herbarium volume. But it is important to note that some taxa are only present in one herbarium and are missing in the rest: 20 in BCN, 18 in BC, four in HGI (Filago lusitanica, Isoetes velatum, Polygonum romanum ssp. gallicum and Ranunculus nodiflorus), two in HBIL (Hesperis laciniata and Teucrium campanulatum) and two in MTTE (Atropa baetica and Asplenium majoricum). These taxa are generally rare with few localities in the study area, and have been only collected once or a few times; this explains why they are only present in one herbarium, usually the closest herbarium of the taxon’s distribution. This fact highlights the importance of the small herbaria as representatives of local floras.

Figure 2. 

Origin herbarium of the specimens included in the dataset.

The scientific names of this dataset are those accepted in the Catalonia Red List, which follow mainly Flora dels Països Catalans (Bolòs and Vigo 1984–2001) and Flora iberica (Castroviejo 1986–2009). The arrangement into families and orders has followed the APG III classification (APG III 2009).

This dataset includes 1,618 records of threatened vascular plants (106 Pteridophyta, 6 Equisetophyta, 36 Lycopodiophyta, 11 Coniferophyta and 1,459 Magnoliophyta). Figure 3 shows the families with more specimens, that usually also have a high number of taxa (families with only three or less taxa have not been represented in the figure). The highest number of records is from Plumbaginaceae with 213 specimens; this family has also the largest number of threatened taxa with 11 species: nine Limonium, one Limoniastrum and one Myriolepis. It is important to note that this family has doubled the number of specimens of the second family more represented, Brassicaceae, with 77 specimens. Plumbaginaceae is a complex group with many endemisms described in the Mediterranean region with non-clear taxonomic status. Its specimens have been collected by many botanists during a large period of time, between 1866 and 2015. Almost 100 specimens have been collected by A. Curcó from 1989 to 1990, during his study of the Limonium genus in the Ebre river delta (Curcó 1992). Moreover, there are two species of Limonium among those with more than 30 specimens (Table 3). Highlight Limonium densissimum (57 specimens, some of them duplicates), a halophyte plant of the W-Mediterranean coast present in the Ebre river delta.

Figure 3. 

Families with 18 or more specimens (number of the taxa in the upper axis and number of specimens in the lower axis).

Some families are overrepresented in the dataset, like Polygalaceae with only one threatened taxon (Polygala vayredae) with 54 specimens (see Table 3) and Zygophyllaceae with also a single taxon (Tetraena alba) with 30 specimens. P. vayredae is a local endemism that occupies only an area of 12 km² but it is very abundant in this area; this taxon was described in 1877 and since then many local botanists have collected it (between 1877 and 2013).

On the contrary, some families with many threatened taxa (seven or more) have few specimens (less than 50), so they are not well represented in the dataset. It is the case of Orchidaceae (nine taxa but only 18 specimens), that are usually not well represented in the herbaria due they are difficult to well press and their flowers quickly lose their color. The low presence of Cyperaceae (seven taxa but only 20 specimens) may be due to the difficulty of the identification of the Carex species, and the scarce presence of the threatened species in Catalonia—they only appear in a few localities in the Pyrenees. Asteraceae (10 taxa and 51 specimens) is one of the families with more threatened taxa and also the richest within plants in the Mediterranean region. The low representation of this family in the herbaria could be explained because five of the ten threatened taxa have three or less specimens; they are endemic species with a narrow distribution area (Centaurea loscosii, Hieracium recoderi or Hieracium vinyasianum) and species recently found in Catalonia as Filago lusitanica (Font and Corominas 2005) and Galatella aragonensis (Arrufat et al. 2008).

The taxa with more specimens in the herbaria (Table 3) are in the most part vulnerable (VU), the UICN category with the lower threat degree, except Stachys maritima that is endangered (EN). This species is characteristic of the coastal sand dune vegetation and has suffered a very strong decline due to its habitat transformation; there are 24 old specimens before 1950 when the species was more or less abundant on the Catalonian coast (Barriocanal and Blanché 2002). Also Maresia nana, a sand dune plant and Halimium halimifolium ssp. halimifolium, a sandy substrates shrub were more or less abundant in the past as certify the 36 and 27 specimens collected before 1950 respectively. The rest of the taxa included in Table 3 are currently more or less abundant in their area, despite their threatened degree. For instance, Salix tarraconensis, an endemism of the Catalonian south mountains, has some populations with more than a thousand of reproductive plants and since its description in 1915 many local botanist have collected it.

The taxa with only a single specimen are shown in Table 4. All these taxa are rare and have in Catalonia only few populations in one or two localities, which explain the low representativeness in the herbaria. Only Cochlearia glastifolia and Cypripedium calceolus are more abundant than the others. Cochlearia glastifolia is an extinct plant in Catalonia that has been found in three localities and it has not been rediscovered since 1949, just the collection year of the BC specimen. Cypripedium calceolus has a wider distribution but also a high protection at regional and international level that prohibits its collection.

It is important to note that some specimens have been collected at the beginning of the 21_st century, and in some cases they are the testimony of the first plant citation in Catalonia. It is the case of Asplenium majoricum, an endemism of Northern Mallorca and the Eastern Iberian Peninsula, recently founded in the south of Catalonia (Curto et al. 2012). Also Cerinthe glabra, a south European orophyte, was found for the first time in Catalonia in 2005 (Aymerich 2008); although Masip and Polo (1987) have mentioned some specimens in the collection of BC-Vayreda that have to be attributed to C. major. Likewise, the Mediterranean plant Sternbergia colchiciflora was found in Catalonia in 2005 for the first time (Molero et al. 2006) and in 2008 a second population has been found (Buira et al. 2009). Finally, another Mediterranean plant, Teucrium campanulatum, was first cited in Catalonia in 2009 (Pedrol and Conesa 2009).

There are 11 taxa of the Catalonian Red List that do not have any specimen from the study area (Catalonia) in the herbaria included (Table 5). It should be noted that, for some of them, there are specimens in those herbaria but from outside of Catalonia (either from other regions of Spain or other countries of Europe or the N of Africa), and therefore not included in this dataset. In many cases, they are plants which Catalonia represents the limit of their distribution. It is the situation of Anthericum ramosum, Carex brachystachys, Epipogium aphyllum and Trapa natans, where Catalonia is in the south limit of their distribution; Colchicum triphyllum and Linaria pedunculata in the north limit or Pilularia globulifera in the east limit. There are some old bibliographic cites of Anthericum ramosum by Vayreda (1882) but the identification of the herbarium material showed that they should be attributed to Anthericum liliago. This example reveals the importance of conserve voucher specimens, as they could be revised by specialists who could verify the plant identification. For some of these taxa we have found specimens in other herbaria not included in the dataset due they aren’t Catalonian herbaria or public collections. It is the case of Pilularia globulifera that Font et al. (1996) found it mixed with Isoetes durieui in a specimen collected by Sennen in 1912; this citation is the unique occurrence of this plant in Catalonia so, it is considered locally extinct. Sáez and Benito (2000) and Guardiola et al. (2013) cite some specimens of Rhinanthus angustifolius. The ancient presence of Trapa natans in Catalonia is confirmed by a Pourret’s specimen collected in 18^th century (Mercadal 2016).

On the other hand, Hieracium recoderi is an endemic taxon of Catalonia with very few localities and in GBIF there are some Catalonian specimens in other herbaria. Woodsia pulchella is an alpine orophyte with a single locality in the Pyrenees and there exists only some specimens (Aymerich and Sáez 2013). Finally, Verbena supina has been cited in Catalonia in 1902 and 1935 but any herbarium specimen has been found to support this cites.

Kingdom: Plantae

Phylum: Coniferophyta, Equisetophyta, Lycopodiophyta, Magnoliophyta, Pteridophyta

Class: Equisetopsida, Filicopsida, Lycopodiopsida, Magnoliopsida (Monocotyledones and Dicotyledones), Pinopsida, Polypodiopsida

Order: Alismatales, Apiales, Asparagales, Asterales, Brassicales, Caryophyllales, Ceratophyllales, Equisetales, Ericales, Fabales, Gentianales, Geraniales, Hydropteridales, Isoetales, Lamiales, Liliales, Lycopodiales, Malpighiales, Malvales, Nymphaeales, Ophioglossales, Pinales, Poales, Polypodiales, Ranunculales, Rosales, Saxifragales, Solanales, Zygophyllales

Family: Alismataceae, Amaranthaceae, Amaryllidaceae, Apiaceae, Araceae, Araliaceae, Asparagaceae, Aspleniaceae, Asteraceae, Berberidaceae, Boraginaceae, Brassicaceae, Butomaceae, Caryophyllaceae, Ceratophyllaceae, Cistaceae, Convolvulaceae, Cupressaceae, Cyperaceae, Droseraceae, Dryopteridaceae, Elatinaceae, Equisetaceae, Ericaceae, Euphorbiaceae, Fabaceae, Gentianaceae, Geraniaceae, Hydrocharitaceae, Hypericaceae, Iridaceae, Isoetaceae, Juncaceae, Lamiaceae, Lentibulariaceae, Liliaceae, Lycopodiaceae, Malvaceae, Marsileaceae, Nymphaeaceae, Ophioglossaceae, Orchidaceae, Orobanchaceae, Plantaginaceae, Plumbaginaceae, Poaceae, Polygalaceae, Polygonaceae, Potamogetonaceae, Pteridaceae, Ranunculaceae, Resedaceae, Rosaceae, Rubiaceae, Ruppiaceae, Salicaceae, Saxifragaceae, Scrophulariaceae, Solanaceae, Thelypteridaceae, Thymelaeaceae, Violaceae, Woodsiaceae, Xanthorrhoeaceae, Zosteraceae, Zygophyllaceae

The present dataset covers all the area of Catalonia (for a description of this area see “Study area” in “Project description”). The 96.48% of the records in the dataset are georeferenced. The coordinate system used is MGRS (UTM squares) and the accuracy of the grids is 10 km² (the coordinates have been generalized to blur sensitive locality information due to the threatened degree of these taxa).

The collecting intensity map (Figure 4) permits to evaluate the regions where threatened plants have been more prospected. The areas with more than 40 specimens (the last category of the legend map) are situated in the littoral regions of Cap de Salou in the south, Delta del Llobregat in the center and Cap de Creus and Aiguamolls de l’Empordà in the north of Catalonia; and in the northeastern mountainous region of Alta Garrotxa and Serra de l’Albera.

Aiguamolls de l’Empordà is the most prospected area and also the region with the maximum number of endangered taxa (Table 6). The botanical interest of this region is high as evidence the different floristic studies done in this area during different periods (eg. Vayreda 1883, Malagarriga 1976, Farràs and Velasco 1994, Gesti 2006). The 80% of the specimens have been collected before 1925, as many of these taxa are now locally extinct in this area. Serra de l’Albera has also a large number of threatened taxa but unlike the previous region, has been visited fewer times as the 70% of the specimens were collected during the study by Font (2000). Cap de Creus is a peninsula of great floristic diversity with abrupt and rocky relief and has been visited by different botanists between 1869 and 2011. Delta del Llobregat has the 86% of the specimens collected before 1935 when this region was more natural and less urbanized than today.

On the other hand, the region of Alta Garrotxa since only two threatened taxa lives in this region has been over-collected: Oplismenus undulatifolius with 6 specimens and the regional endemism Polygala vayredae, with 51 specimens yet explained above (see Table 3).

Figure 4. 

Distribution map of the number of specimens for UTM grid of 10 km².

If we evaluate the collecting intensity map separated for each herbarium (Figure 5) we can see that local herbaria like HGI, HBIL and MTTE host a good representation of specimens from its surrounding area. In the case of the biggest herbaria (BC), the regions most prospected match those indicated in Table 6: Aiguamolls de l’Empordà, Delta del Llobregat, Cap de Salou and Alta Garrotxa. However, in BCN herbarium the most prospected area is Delta de l’Ebre, with 100 specimens collected during the floristic study of this region by Curcó (2003), although there are also a high number of specimens from Cap de Creus collected during the studies of Franquesa (1995) and Sáez (1997).

Figure 5. 

Distribution map of the specimens for UTM grid of 10 km² for each herbarium.

Table 7 shows the number of specimens and taxa of hotspot areas (with elevated number of threatened taxa) designated as Important Plant Areas (IPA) in the Red Book of Catalonia. In fact, all they have different protect regulation included in the Plan for Spaces of Natural Interest (PEIN, DOGC 1992) except the region of Empúries-l’Armentera situated in the littoral, with any protection directive. The most restricted protection is for Aigüestortes, situated in the east of the Catalonian Pyrenees and catalogued as National Park in 1955, so legal permits are needed to collect plants. But in fact, only 22% of the specimens have been collected before this regulation and the 69% have been collected between 1978 and 2009 by the University of Barcelona botanist team that studied this region (Carrillo and Ninot 1992, Guardiola et al. 2009).

Another important region is Ivars d’Urgell (31TCG31), a small area of halophilous and gypsum vegetation with 8 threatened taxa and included in the PEIN; this region is represented in the herbaria by 6 taxa and 17 specimens.

On the other hand, some UTM squares with a high number of threatened taxa have a poor presence in the herbaria. In some cases because they are littoral squares with a large part of the area in the sea like 31TBE99 and 31TCE09 from Delta de l’Ebre and 31TEG17 from Cap de Creus. But in other, the prospecting intensity is too low relating the number of threatened taxa; for instance, 31TCF55 in the littoral of Tarragona with only 10 specimens collected between 1893 and 1993 and 31TBF71 in the mountainous Massís del Port in the south with 11 specimens collected between 1917 and 2008.

In Tables 6 and 7 we can see that in some cases the number of taxa included in the dataset for each UTM square is lower or higher than the one of the Red Book, Figure 6 shows these differences. In the 34.26% of the squares the difference is zero (grey color), indicating that all the taxa cited in this book have minimum a specimen in the herbaria studied. The 45.37% of squares have a positive difference (colored yellow to red), meaning that the dataset doesn’t include all the taxa published in this book. The regions less representatives in the herbaria (red squares) are in the south: two squares in Delta de l’Ebre yet indicated in Table 7.

Figure 6. 

Comparative map of the number of taxa of the dataset and that according to Sáez et al. (2010: 733). Gray color indicates that all the taxa cited in this book have a specimen in the herbaria studied; yellow-red color indicates that the dataset doesn’t include all the taxa published in this book and green color indicates that there are more taxa in the dataset that those published in this book.

The 20.37% of the squares have a negative difference (green color), indicating that there are more taxa in the dataset than in the Red Book. This is due, on one hand, to new citations published by different local botanists after the Red Book publication in 2010. For instance, in the UTM square 31TDG19, situated in La Cerdanya in the center of the Catalonian Pyrenees, the dataset includes specimens of Gagea pratensis and Gagea reverchonii published by Aymerich (2013) and so not indicated in the Red Book published three years before. This fact shows that herbaria are dynamic libraries of taxa if we compare with books that may become obsoletes once published. On the other hand this negative difference may also be due to some specimens that can provide new citations and are still to be studied and published. This second fact demonstrates that herbaria are important sources of hidden data.

Finally, highlight that for more of the 50% of the squares (difference zero or negative) all the taxa have almost a specimen which indicates the good representativeness of this kind of flora in the herbaria.

The 92.27% of the specimens have the collecting year indicated in the label. Among this, the temporal coverage is between 1861 and 2015 (Figure 7). There are 6 specimens from the Salvador’s collection conserved in the BC herbarium, collected between 17_th and 18_th century (Ibáñez 2006), but without specific year in the label (in the figure are indicated as before 1860). In some cases, these old specimens are the testimony of the presence of a taxon in an extinct locality as the specimens of Hydrocotyle vulgaris and Stachys maritima from the coast of Barcelona.

The maximum number of specimens was collected since 1980 when the number of botanists dedicated to floristic studies significantly increases. After the regulation of the threatened flora in Catalonia with the publication in 2008 of the Catalogue of Endangered Flora (DOGC 2008) the specimens collected have been declined and there are only 112 specimens between 2009 and 2015 when legal permits are needed (the 6.92% of the whole dataset).

On the other hand, Figure 8 shows that the most part of specimens have been collected in spring and summer, when almost all the taxa are in flowering state in the study area.

Figure 7. 

Collecting years according the specimens labels.

Figure 8. 

Collecting months according the specimens labels.

Object name: Darwin Core Archive Threatened plants of Catalonia.

Character encoding: UTF-8

Format name: Darwin Core Archive format

Format version: 1.0

Distribution: http://www.gbif.es/ipt/resource?r=threatenedCAT

Licenses of use: This Dataset is made available under the Open Data Commons Attribution License: http://www.opendatacommons.org/licenses/by/1.0

Metadata language: English

Date of metadata creation: 2016-19-12

Hierarchy level: Dataset

We appreciate the support of the Generalitat de Catalunya, government of Catalonia (‘‘Ajuts a grups de recerca consolidats’’, 2014SGR514) for the realization of this article. We thank David Pérez Prieto for his help with the maps elaboration.