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.
Starting from Seed. A cool-weather vegetable, turnips do best in spring and fall. You can easily plant for two crops, and its fine to direct seed into the garden in either season. For your first planting, get the seeds out into the garden about 3 to 4 weeks before your expected last frost date.