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.
Growing maple trees from cuttings. Growing maple trees from cuttings is an easy way to get free saplings for your garden. Take 4-inch cuttings from the tips of young trees in midsummer or mid-autumn, and remove the leaves from the lower half of the stem. Scrape the bark on the lower stem with a knife and then roll it in powdered rooting hormone.