March 19, 2009 -- An Australian native plant is using chemical warfare to prevent its bright red flowers being eaten, according to a new study. The finding challenges conventional thought that flowers evolved as a way for plants to attract birds and animals that help them cross-pollinate. In the latest edition of New Phytologist, Byron Lamont and his colleagues suggest the animals that may eat the plant also play a role in its floral development. "Flowers are not just an evolutionary response to pollinators, but also to herbivores," said the director of the Center for Ecosystem Diversity and Dynamics at Curtin University of Technology in Western Australia. Lamont said the team studied 51 species of Hakea, and found they could be easily divided into two groupings. Insect-pollinated species have predominantly tiny, white flowers surrounded by spiky, dense foliage, which they suggest stops animals such as emus and cockatoos from eating the flower. Related Content: Bird-pollinated species instead have soft open leaves and bright, easily accessible, usually red, flowers with room for birds to land on stems. This makes the plant vulnerable to being eaten by emus and cockatoos. Lamont and colleagues travelled to the heathlands north and south of Perth to collect samples of Hakea. They macerated the flowers on-site and then used an enzyme and a strip of paper that was sensitive to cyanide to test for its presence. He said they found that plants with red flowers contain 10 milligrams of cyanide per gram, enough to make an animal sick. Co-author Mick Hanley, of the University of Plymouth, said animals that eat the red Hakea flowers may learn to associate the color with the bitter taste produced by the cyanide. "The color red acts as a warning to large vertebrate herbivores like emus, parrots and kangaroos that the flower contains distasteful or even poisonous cyanogenic compounds," he said. "It seems that Western Australian plants have not only developed a remarkable defense against would-be flower predators, but that they also clearly advertise the fact." Lamont, who holds a personal chair in plant ecology, believes the poison came first in the plant's evolution. "Bird pollination came after plants were already having to protect themselves against herbivores," he said. Get More NewsSpiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates.Oldest Hebrew Writing Possibly FoundAncient inscriptions on a 3,000-year-old pottery shard could make history.Rare, Prehistoric-Age Reptile Found in N.Z.A tuatara has been spotted on the New Zealand mainland for the first time in 200 years.Iceman Has No Living RelativesOetzi, the 5,300 year-old frozen mummy, left no living genetic legacy.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.It's Official: People Are Warming the PolesHumans are conclusively to blame for polar warming, say scientists.Eight-Armed Animal Preceded DinosaursWhat may be one of Earth's first animals was no bigger than a coaster and had eight arms.Phoenicians Live on in People's GenesOne in 17 Mediterranean men may be descended from ancient Phoenicians.Pesticides, Fertilizers Linked to Frog DeclineA pesticide is found to promote parasites among amphibians.Hubble Telescope Taking Photos AgainThe Hubble Space Telescope is once again snapping stunning photos of the universe.Andean Mummy Hairs Show Hallucinogen UseScientists find direct evidence of hallucinogenic drug use among ancient Andeans.Opals on Mars Reveal Planet's Long Wet PastOpals found on Mars suggest the planet has been wet for much longer. |
advertisement
Put Discovery News on Your Site!
|
-
our sites
-
video
mobile
-
shop
-
stay connected
-
corporate
