Plants are designed to survive and reproduce through various devises. The odors of sweet-smelling spring flowers attract honeybees, resulting in pollination. Fragrant roses delight humans and attract bees. The fetid odors of carrion flowers are of rotting flesh, attracting carrion beetles, certain flies and midges. Other flowers including some orchids and the male flowers of carob trees, are unpleasantly scented to the human nose, but attractive to flies.
Dutchman's Pipe Flowers
The petals of carrion flowers carry the odors of rotting meat. The European Dutchman's pipe (Aristolochia clematitis) has a tubular flower resembling an old-fashioned smoking pipe. The upright blossom emits a fetid odor, drawing small gnats down the slippery floral tube where they are trapped and fed for several days. Laden with pollen, they are released to repeat the process. A. fimbriata is a Dutchman's pipe native to Argentina, attracting small flies. The Brazilian Dutchman's pipe, A. gigantean is one of earth's largest flowers, emitting a strong, nauseating odor from a wine-colored flower up to 12 inches across.
The Arum plant family contains several malodorous plants. Skunk cabbage (Symplocarpus foetidus) is native to North America and has a strong odor of skunk. Lords-and-ladies (Arum maculatum) are European plants that smell strongly of feces or rotted meat. The dead-horse arum lures blowflies with its very strong odor of a dead animal carcass, trapping them until the plant releases pollen, dusting them as they escape. The corpse flower (Amorphophallus titanium) is an arum native to Sumatra in Indonesia. A specimen flowered at the New York Botanical Garden in 1937 with a floral structure 8 feet tall and 12 feet across, releasing a remarkably strong, unpleasant odor. The tuber that produced this specimen weighed more than 100 pounds.
Flowers that considered especially fragrant include Night-blooming Jasmine, an evergreen shrub from the West Indies; Michelia alba, a flowering tree originating in the Himalayas; and Sweet Olive, a shrub from Asia. Where commercially grown, citrus groves permeate the surrounding area with fragrance when in bloom. Tuberoses, freesias, Oriental lilies and hyacinth have very fragrant flowers blooming from bulbs. Fragrant lily of the valley grows from pips. The fragrances of lilacs and gardenias are legendary. The annual flower matthiola or stock is especially fragrant. Mattiola longipetala, evening-scented stock, releases its fragrance at night. What is pleasant to some may be overpowering to others, and atmospheric conditions affect how fragrance is carried in the air.
The James Alexander Gamble Fragrance Medal and the International Rose Trials at Tollcross Park's Tollcross Fragrance Prize are internationally recognized awards for fragrance in roses. Roses that have won such recognition include Princess Alaxendra of Kent, Helen Robinson, White Gold, Jubilee Celebration, Nobel Antony, Fragrant Cloud, Angel Face, Double Delight, Mister Lincoln, Sweet Chariot, Sheila's Perfume, Granada, Tiffany and Papa Meilland. The perception of rose fragrances is somewhat subjective. Many varieties that have not won awards are very fragrant. Full fragrance in rose blossoms may be expected on mature plants.