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.
Maple seeds dropping in soon. 2012 provides a bumper crop of these maple âhelicoptersâ and âwhirligigs.â. Most of the horticultural news this spring has been dominated by what we donât or wonât have this year due to late frosts; peaches, cherries, blueberries, plums and on and on. One crop we have in abundance, however, is maple samaras.