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.
Adopted on June 4, 1949. A favorite Tree was first selected by a vote of Wisconsin school children in 1893. The sugar maple tree, (Acer saccharum,) won, followed by oak, pine and elm. Another vote was conducted in 1948 among school children by the Youth Centennial Committee.