Table 1.

Summary of database columns.

Column name	Description
Database ID	Unique database identification number assigned to each record
Country	Name of country or biogeographic unit (e.g., Island of Ireland) to which the red list belongs to
Sub-country	Region within country (relevant only for Belgium)
Kingdom	The plant kingdom as Plantae
Family-original taxonomic name	Family of the original taxonomic name (i.e., taxonomic name extracted from countries’ red list)
Original taxonomic name	Taxonomic name extracted from countries’ red lists
Name backbone used	Taxonomic name backbone (TNB) used to determine the most up-to-date taxonomic status - and to establish accepted taxonomic name with scientific authorships (POWO – The Plants of the World Online; WFO – World Flora Online)
Life Sciences Identifier (LSID)-accepted taxonomic name	Unique identifiers assigned by International Plant Names Index (IPNI) to identify each taxonomic name. In the absence of LSID, unique identifier of the record.
Family-accepted taxonomic name	Family of the accepted taxonomic name assigned by authors using summarised TNBs and confidence levels
Accepted taxonomic name without authorships	Accepted taxonomic name without scientific authorships assigned by authors using summarised TNBs and confidence levels
Authorships-accepted taxonomic name	Scientific authorship for accepted taxonomic name assigned by authors using summarised TNBs and confidence levels
Accepted taxonomic name with authorship	Concatenation of accepted taxonomic name with scientific authorships above
Confidence level	Level of precision for assigning an accepted taxonomic name with scientific authorship
Confidence level description	Detailed description of confidence level determination
Red list category	Red list category listed in original red lists
Standardized red list categories	Red list category harmonized to reflect the currently valid IUCN regional red listing categories (IUCN 2012). The harmonisation process is described in Supplementary Table S2.
References	The original source from where the data were extracted (e.g., book, article, report, website, etc.). Where applicable, references were translated to English. References are available in the original and English language in Supplementary Table S1.