Nancy M. sends this picture of a Dragon Arum (Dracunculus vulgaris) in bloom in her garden, with the message "Blowflies just love it."
After some research, I learned it's because the Dragon Arum belongs to a class of plant known as
Unlike the fragrant blossoms that attract bees, butterflies and moths, carrion flowers simulate the odor of a rotting carcass and attract carrion beetles and a variety of flies including blowflies, flesh flies and midges.
The European relatives "lords-and-ladies" (Arum maculatum) and "dragon arum" (Dracunculus vulgaris) emit rather unpleasant odors resembling carrion or fresh feces.
Although these plants are inconspicuous most of the year, their showy spathes and stench are unmistakable during late spring and summer.Here is the Wikipedia entry:
Dracunculus vulgaris is a species of aroid in the genus Dracunculus and is known variously as the Dragon Arum, the Black Arum, the Voodoo Lily, the Snake Lily, the Stink Lily, the Black Dragon, Dragonwort, and Ragons. In Greece, part of its native range, the plant is called Drakondia, the long spadex being viewed as a small dragon hiding in the spathe.Lots of pictures here. USDA information here.
It is native to the Balkans, extending as far as Greece, Crete and the Aegean Islands, and also to the south-western parts of Anatolia. It has been introduced to the United States and is currently present in the states of Oregon, California and Tennessee as well as the commonwealth of Puerto Rico.