Posting images from Wageningen University's online archive of 1,180 root system drawings.

"The outcome of 40 years of root system excavations in Europe."

https://www.openculture.com/2022/01/1100-delicate-drawings-of-root-systems-reveals-the-hidden-world-of-plants.html

"Sometimes the researchers spent their holidays making excavations and drawings."

https://images.wur.nl/digital/collection/coll13/

Shout-out to @liaizon for the idea.