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.
Red MapleThe red maple tree grows in zones 3 to 9, the red maple tree is deciduous, and it loses its leaves every year in the fall then grows new leaves in the spring. The red maple tree grows at a moderate to rapid rate. The red maple tree grows best in bright sun to partial shade.