The following blog was written by Linde Hess a digitiser in the Herbarium.

Since 2021 we have increased our digitisation capacity with the goal of getting to 1 million specimens imaged by Autumn 2024. Each digitiser is assigned a family of plants to work through. This series of blogs will spotlight the families that have been completed by a member of the team.

The Euphorbiaceae are the 5th largest flowering plant family (Britannica1). Some well-known members of this family are the castor-oil plant (Ricinus communis), poinsettia (Euphorbia pulcherrima) and rubber (genus Hevea). 

Plants have evolved three photosynthetic pathways, each in response to distinct environmental conditions, resulting in differences in their ecological patterns of growth and distribution. All three photosynthetic pathways are represented within the Euphorbiaceae family. The pathways are the C3, the C4 and Crassulacean Acid Metabolism (CAM) pathways. You can find a very clear and accessible explanation of  the differences between these pathways here2. Remarkably, the genus Euphorbia includes species with the C3, C4 and CAM types of photosynthesis CO2 fixation and is perhaps unique in this respect within the angiosperms (Batanouny et al., 19913). 

Euphorbiaceae cabinets
Panoramic photo of the cabinets which hold our vast Euphorbiaceae collection. 

Our collections at Edinburgh

We currently have over 22,000 Euphorbiaceae specimens in our herbarium. This (luckily well-curated) family takes up 45 of our herbarium cabinets. It was the first family worked on when I started at the herbarium, and I was very happy to wrap it up after dedicating 10 months (not 24/7!) to it.  

Prior to digitistion of the Euphorbiaceae we had 8,757 specimens in our database. Once completed we had 22,447 specimens, adding 13,690 records to our database. We currently hold 625 type specimens for taxa in Euphorbiaceae

Specimens of Euphorbiaceae can be searched on our online catalogue here.

Top 5 regions

No. of SpecimensHerbarium Filing Region
6,715Europe (excl. Britain & Ireland)
3,564West Asia & Egypt
3,540Inner China, Korea & Taiwan
2,582India Bangladesh & Pakistan
1,090North America

Top 5 Genera

No. of SpecimensGenus

Interesting specimens

E00621368 6

A root system was kept witht he specimen of Mallotus japonicus (L.f.) Mull.Arg. (E00621368). These plants were cultivated at RBGE, and was interesting as root systems aren’t often preserved in herbarium specimens.

E00320200 6

The colour of fruits of this Mallotus tree from Cambodia specimen have been beautifully preserved (E00320200). 

Help us transcribe our specimens

We are currently running an expedition to transcribe our Euphorbiaceae specimens on DigiVol. You can help us by joining this series of expeditions which seek to complement this work of our digitisers by enriching the basic online catalogue records with specimen label data.

If you’d like to help with the transcription of our specimens you can join here.


  1. Euphorbiaceae (2024) Encyclopaedia Britannica. Available at: (Accessed 29 Feb 2024)  ↩︎
  2. Forseth, I. N. (2010) The Ecology of Photosynthetic Pathways. Nature Education Knowledge 3(10):4 ↩︎
  3. Batanouny, K. H., et al. Photosynthetic Pathways and Ecological Distribution of Euphorbia Species in Egypt. Oecologia, vol. 87, no. 4, 1991, pp. 565–69. JSTOR, ↩︎