Have you ever been walking in the woods and noticed the smell of sweaty feet?
A botanist who was conducting a routine survey of plants in Yosemite started smelling something that she described as a "horse corral on a hot afternoon." Being a curious scientist, she followed her nose and found that the smell was coming from delicate yellow orchid flowers of less than a quarter of an inch wide.
It turns out that she had discovered a rare orchid species that flourishes only in the wet meadows of Yosemite National Park between 6,000 and 9,000 feet. Apparently, the Yosemite bog-orchid emits the smelly-foot odor to attract pollinators such as flies that are attracted to such odors.
There are actually many flowers that produce odors that are offensive to people. For example, plants in the arum family, like the skunk cabbage or its giant relative, the Titan arum or corpse flower produce compounds that can smell like rotting flesh. To further help attract pollinators, the arum flowers actually heat themselves to make the odors more volatile so they can attract flies from far and wide.