The distribution of collection dates (by year, if known) of the specimens in the dataset for each providing institution. The heat colour indicates the number of specimens for each 10 year time period. Year data were extracted from Darwin Core eventDate and verbatimEventDate if these were in ISO 8601 standard. Codes for the herbaria follow Table 2.

  
  Part of: Dillen M, Groom Q, Chagnoux S, Güntsch A, Hardisty A, Haston E, Livermore L, Runnel V, Schulman L, Willemse L, Wu Z, Phillips S (2019) A benchmark dataset of herbarium specimen images with label data. Biodiversity Data Journal 7: e31817. https://doi.org/10.3897/BDJ.7.e31817