These trees are taking "leaning in" to a whole new level. Cook pines (Araucaria columnaris) tilt south in the northern hemisphere and north in the southern hemisphere but always leaning towards the equator. Scientists measured them across five continents, but the reason behind this mysterious leaning is still anyone's guess—it could be sunlight, gravity, magnetism, or a mix of these factors. (Nag on the Lake)
Matt Ritter, a professor at California Polytechnic State University in San Luis Obispo, noticed this peculiar pattern while studying the Cook pine for a book on urban trees of California. Ritter and his colleagues studied 256 Cook pines across five continents and found that they tilt by an average of 8.55 degrees, which is double the tilt of the Leaning Tower of Pisa.
Moreover, Cook pines slant more as they move away from the equator in both hemispheres, with one tree in South Australia slanting at 40 degrees. This pattern is shocking and distinct, according to Ritter.