Karl Gustav Sanio (5 December 1832 – 3 February 1891) was a Prussian botanist and served as a professor of botany at the University of Königsberg.
He observed patterns in the growth of plant vasculature and wrote several articles on the organization of wood and cambium.
He examined patterns in the size distribution of the xylem vessels in five statements known as Sanio's laws was also among the first to describe the formation of compression wood by conifers.
He received a doctorate in 1858 and then taught botany after moving back to Königsberg.
[1] In 1872 he published a series of observations on a pattern in the size of xylem tracheids, increasing in size from the top of a tree to a certain height after which they decrease again to the base of the tree.