While walking past the fenced yard of a large house in Georgetown, DC today, I noticed several plants that had twisted themselves around the posts. Most were left-handed spirals or helices (left). But there was one that was right-handed (right).
I am not much of a plant identifier and without leaves I couldn't even tell if they were all the same species. I don't know if the spiraling direction of climbing plants is determined genetically or randomly by the external circumstances. If I pass by the same spot in the spring I hope to remember to check if the right-handed plant is the same as the others.