Herbarium of Vascular Plants Collection of the University of Extremadura (Spain)

Abstract The herbarium of University of Extremadura (UNEX Herbarium) is formed by 36451 specimens of vascular plants whose main origin is the autonomous region of Extremadura (Spain) and Portugal, although it also contains a smaller number of specimens from different places, including the rest of peninsular Spain, the Baleares Islands, the Macaronesian region (Canary Islands, Madeira and Azores), northwest of Africa (Morocco) and Brazil. 98% of the total records are georeferenced. It is an active collection in continuous growth. Its data can be accessed through the GBIF data portal at http://data.gbif.org/datasets/resource/255 and http://www.eweb.unex.es/eweb/botanica/herbario/. This paper describes the specimen associated data set of the UNEX Herbarium, with an objective to disseminate the data contained in a data set with potential users, and promote the multiple uses of the data.


The UNEX Herbarium
Established in 1986, the specimens that the herbarium of vascular plants collection of University of Extremadura (UNEX Herbarium) incorporates is the result of the work of collections and identifi cations by diff erent researchers, associated with the Botany Area (Department of Plant Biology, Ecology and Earth Sciences) of the University of Extremadura. Chief amongst these individuals include: Professor Juan Antonio Devesa, founder and director of the herbarium until 2004, and Dr. Trinidad Ruiz, curator and current director of the UNEX Herbarium. Signifi cant contributions have also been made by Professor Ana Ortega-Olivencia, Dr. Rafael Tormo, Dr. Josefa López, and Dr. Tomás Rodríguez-Riaño. Other researchers who contributed to the growth of the UNEX Herbarium includes, Mª Carmen Viera, Jacinto Pedro Carrasco, Adolfo Muñoz, Inmaculada Montero, and Francisco Mª Vázquez. In addition, the disinterested work developed throughout time by a lot of students of the University of Extremadura, especially, Mª Luisa Navarro Pérez and Dr. Francisco Javier Valtueña. Th e development of diff erent research projects has made it possible to improve the quality of the herbarium. Among them, the numerous compilations carried out by diff erents members of the Botany Area in order to elaborate the fi rst fl ora of the Extremadura region (Devesa 1995) or the synthesis of diff erent taxonomic families or genera for Flora Ibérica (http://www.fl oraiberica.org/). Additionally, 4.5% of the material comes from the purchase of part of the herbarium of Dr. J.V.C. Malato-Beliz.
Limited and unpredictable funding has always pose challenge for ensuring sustained growth of the collection facility since its establishment.
Th e specimens better represented in the database correspond to elements of the Mediterranean forest and/or scrubland. Th ese specimens are developed under a seasonal climate of mild winters and hot and dry summers, with abundant rainfall in autumn and spring. Frequent in this climate are forest fi res, to which the vegetation is adapted. Specimens from Brazil (except one specimen collected in the state of Santa Catarina), are collected in the state of Río Grande do Sul. Th is state has a humid subtropical climate and a hydrography classifi ed into three major regions: Uruguay River Basin, Guaiba River, and Litoral.

Method step description
Dried and pressed method has been adopted for preservation of the specimens deposited in the collection. After collection of specimens in the fi eld (see "sampling description" for the collection protocol) they are pressed and dried with the aim of adapting them to a fl at surface and remove water from the tissue, thereby preventing their degeneration or attacks by bacteria, fungi or insects that would destroy them. Assembly of specimens: Th e dried material is mounted on a holder constituted by an A3 cardboard (42 × 29.7 cm) and a resistant paper (so-called jacket) dimension A2 (42 × 59.4 cm) that perfectly covers the cardboard, thus protecting the specimen. Th e assembly is made on the cardboard with transparent tape, allowing both that the specimen be tighten to the holder and that the assembly be aesthetic.
Registration of herbarium specimens: After assembly, specimens are registered and labeled. Registration is done in a database (Microsoft Offi ce Access Database → Dar-winCore 1.2) in which each specimen is assigned a reference number allocated consecutively. Th e information contained in the record of each specimen is: institution owner of the herbarium, reference number, scientifi c name of the family and species, date of collection, georeferencing data (country, province, town), habitat, Legitimavit, and Determinavit. All log data are printed and constitute the sheet label.
Treatment of specimens: Before putting the specimens in the herbarium they are stored in hermetic plastic boxes and kept for 72 hours in cold storage (freezers) at -40°C. In this way the material is decontaminated from possible attacks of pathogens that can destroy them and the rest of material already in the herbarium. Storage of specimens: Finally, the specimens are kept inside compact enclosures in shelves where they are arranged taking into account the four main groups: pteridophytes, gymnosperms, monocots, and dicots. Within each main group the specimens are alphabetical arranged by families and genera.

Study extent description
Iberian Peninsula is the most signifi cant geographic zone represented in UNEX Herbarium. Figure 6 depicts the collections from various provinces of Iberian Peninsula. Over 5000 specimens are collected from two provinces (Badajoz and Cáceres). Two provinces (Cádiz and Almería) contributed specimens in the range of 500-1500. Th e specimens collected from morocco (111 sheets) are representatives for an area greater than 50% of the country (Fig. 7a). Conversely, specimens from Brazil (721 sheets) cover not more than 3% of the area of the country (Fig. 7b).

Sampling description
As evident from the previous section, the specimens deposited in the UNEX Herbarium comes from diverse regions, which is outcome of several research projects depositing the specimens. As a result, specimens are not collected using a single, uniform protocol. Of the materials from donations or purchases (e.g. herbarium of Dr. J.V.C. Malato-Beliz) the protocol followed for the collection of specimens is unknown. Th e methodology used in collecting plants by researchers from the Botany Area may change depending on the objectives pursued by the work they are carried out for.
In general, collection takes place following previous available references drawn from scientifi c works, herbarium material or indications from reliable collectors. Th e collection campaigns are designed to be more or less exhaustive of diff erent available areas depending on the purpose of the collection (e.g. for taxonomic works, we do exhaustive inspections of whole territories with expansion of the collection area beyond known indications).

Quality control description
Each specimens and associated data record was subjected to two quality procedures; (a) taxonomic determination or identifi cation and (b) geo-referencing. For taxonomic identifi cation, trusted experts were contacted, the 85% of the material has been identifi ed by investigators of the Botany Area of the University of Extremadura. Th ese experts have authored number of monographs, which include Vegetación y Flora de Extremadura (Devesa 1995) in which 2050 taxa's are described. Other includes Las Gramíneas de Extremadura (Devesa 1999) or the volumes of Flora iberica XV (Devesa et al. 2007) com-prising the taxonomic synthesis of families Adoxaceae, Caprifoliaceae, Dipsacaceae, Rubiaceae and Valerianaceae, and XVI (under edition, see http://www.fl oraiberica.org/) in which these experts are responsible for the genera Arctium , Atractylis , Carlina , Crupina ,  Cynara , Echinops , Onopordum , Rhaponticum , Saussurea , Staehelina , and Xeranthemum . It is worth also to note the publications of new species of fl ora ( Centaurea bethurica , Devesa and López 2008;Scrophularia fontqueri Ortega-Olivencia and Devesa 1998;Galium moralesianum and G . talaveranum Ortega-Olivencia and Devesa 2003;Galium belizianum Ortega-Olivencia et al. 2004), whose typus are preserved in UNEX Herbarium.
Besides the above mentioned authoritative literature, experts have also relied upon the biology of the reproduction of diff erent taxa of the family Fabaceae , 2000, 2005, Rodríguez-Riaño et al. 1999a, 1999c, 2006, Valtueña et al. 2007, 2008a, 2008b, 2010a, 2010b, 2011 or the genera Drosophyllum (Ortega-Olivencia et al. 1995 or Scrophularia (Ortega-Olivencia and Devesa 1993a, 1993b, Valtueña et al. 2013. Use of these literature resources and long standing experience of the researchers high degree of confidence to the taxonomic identifi cation of the specimens. Th e 98% of the records in the collection are georeferenced. A total of 58.38% have MGRS coordinates and the rest geographical coordinates. Th e MGRS coordinate system has been transformed into geographical coordinates through a geographic calculator (http://www.asturnatura.com/sinfl ac/calculadora-conversiones-coordenadas.php), while at the same time maintaining the MGRS coordinates in the database. Th e accuracy of these coordinates grids varies from 1 km 2 to 10 km 2 . Th e geographical coordinates have been taken through the description of localities and search of these localities in Google Earth (http://www.google.com/earth/index.html). Th e accuracy of geographic coordinate values also varies between 2 and 12 km depending on the number of decimal places contained.