decussate

“Decussate” [dih-KUH-seyt]

From the Latin decussatus, meaning “divided crosswise,” the word also connects with the Latin decussis, which describes both the figure X and Roman numeral for 10.

Words beginning with “dec-” can refer both to X and the number 10. In ancient, ancient Rome, December was originally the 10th month of the year. July and August were added to memorialize Julius Caesar and Augustus Caesar.

In botany, the term “decussate” describes pairs of leaves with stems at right angles to one another that cross paths as they grow!

Photo from ​The Digital Atlas of Ancient Life, a project managed by the Paleontological Research Institution, Ithaca, New York.