How drought stress affected root structure: very nice figures from 1934 (84 years ago!!!).
Goossens, A. P. (1935). Notes on the anatomy of grass roots. Transactions of the Royal Society of South Africa, 23(1), 1-21.
https://t.co/QYhkyTbeOx
Root biologist must read this paper from 1893, easy to find in Google!
Maxwell, F. B. (1893). A comparative study of the roots of Ranunculaceae. Botanical Ga-zette, 18(1), 8-16.