Progesterone. Print | Email article to a friend | Last updated: January 14, 2015. Progesterone is a hormone released by the corpus luteum in the ovary. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. It may also be involved in the growth of certain cancers.
Maple helicopters fall before the leaves drop from the trees. Maple trees (Acer spp.) produce winged seeds called double samaras, which twirl to the ground in late summer or early fall. They resemble helicopters in motion, earning them the common name of helicopters or whirligigs.
Sugar maple trees are considered a slow growing tree, maybe 1 ft. per year. I would highly recommend going to your local plant nursery during late October and find a nice yelow tree. You could ask the nursery owner to show you the maple, poplar, and oak trees that are turning yellow and compare them.