By Alister Doyle

OSLO (Reuters) – A tree that covers a large area of eastern Ethiopia but has only recently been categorized by botanists raises hope for finding new {www:species} elsewhere, experts said.

The acacia fumosa tree, which grows in an area the size of the island of Crete, was not “found” for scientific purposes until 2006-7, mostly likely because its main habitat is a war zone.

“I have spent a lifetime looking at plants and describing species — it knocked me sideways when I heard about this tree,” David Mabberley of the Royal Botanic Gardens in Kew, England, told Reuters.

“The total numbers must be in the millions,” he said of the pink-flowered, 6-m (20-ft) tall tree that covers hillsides in an {www:inaccessible} area of 8,000 sq kms (3,100 sq miles) near the border with Somalia.

In an article in Friday’s edition of the journal Science, he wrote that the tree had been overlooked by generations of botanists, apparently because of few visits to the area where the Ogaden National Liberation Front is fighting for autonomy.

The discovery was an encouraging sign that other overlooked large species might still be found, from rainforests to the ocean depths. Still, he said, scientists were “highly unlikely” to find another tree dominating such a large area.

The discovery contrasts with gloom about destruction of habitats and global warming threatening more extinctions. Environment Ministers of the Group of Eight are meeting in Italy from April 22-24 discussing ways to slow a loss of biodiversity.

“It’s an upbeat story for a change,” Mabberley said. The tree was found by Swedish botanist Mats Thulin and previously described in a Nordic journal.

People in the sparsely populated region did not exploit the tree except for firewood but it might have commercial uses, for instance in gum used for foodstuffs or glues.

About 10,000 new species of plants or creatures are described worldwide every year, most of them tiny, he said.

COELACANTH

Among exceptions, a coelacanth fish known only from fossils was caught off South Africa in 1938. The wollemi pine, also known from fossils, was found in Australia in 1994. And the saola antelope in Vietnam and Laos was identified in 1992.

“I suspect there are still large species out there to be discovered,” Craig Hilton-Taylor, head of the International Union for Conservation of Nature’s Red List of endangered species, told Reuters.

He said that countries that have suffered conflicts — such as Democratic Republic of Congo, Cambodia or Colombia — were likely places to find overlooked species.

And some types of beaked whales that dive to great depths were only known from washed up corpses. “There are probably still a few things in the deep ocean we haven’t found,” he said.

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More by Susan Milius of Sciencenews.com

An acacia in northern Africa that grows six meters tall and dominates the {www:landscape} across an area almost three times the size of Rhode Island is new to science.

“It’s astounding,” says David Mabberley of the Royal Botanic Gardens in Kew, England. He summarizes the findings in the April 24 Science, though the tree was officially named Acacia fumosa online in the Nordic Journal of Botany in September 2008.

Finding a new species in itself isn’t such a surprise, he says. Scientists describe and give Latin names to some 10,000 new organisms a year. About 2,350 of these are flowering plants, with a new one from Africa appearing on average every weekday. Many of these new names go to plants that have been languishing misidentified or unidentified in collections, Mabberley says, and the complete surprises are typically uncommon plants or those that have tiny ranges.

But no herbarium specimens or botanical mentions of the new acacia existed, even though it’s widespread in its homeland, says Mats Thulin of Uppsala University in Sweden, who named the plant. He has named several hundred plants but never seen a case like this.

Science got such a shock from the tree because the acacia grows in Ethiopia’s Somali National Regional State, or Ogaden. Though politically part of Ethiopia, the sparse population of the region is mostly ethnic Somali, Thulin says. The Ogaden National Liberation Front is fighting for independence and has made traveling to the region perilous.

Thulin, who spent 18 years as editor of Flora of Somalia, had never visited Ogaden until 2006, when he joined a German zoologist who had arranged to study antelopes there.

“What happened to us several times both in 2006 and 2007 was that a group of rebels was suddenly standing on the road with machine guns directed toward us,” Thulin says. The scientists carried no weapons and had put a sign on their car saying so. Each time, after an hour or two of questioning, the armed party let them go. “An American, an Ethiopian or someone working for the Ethiopian government would have been in big trouble,” he says.

Almost immediately on seeing the acacia, Thulin says, he recognized it as an unknown species. It had unusual, smooth, gray bark, for example. On a later trip, he discovered that it burst into pink, sweet-smelling blooms during the dry {www:season}, when no leaves were on the trees. Its relatives bloom in yellow or creamy flowers during the wet season.

With a bit of travel and some help form Google Earth, Thulin realized how widespread the acacia is in its arid habitat. The tree provides vegetation in a landscape too dry for perennial grasses. And, like other acacias, has glands where ants sip nectar, so there may be a tree-insect mutualism.

Finding another such surprise may not be too likely, according to Tom Daniel, botany curator at the California Academy of Sciences in San Francisco. New species, yes. Plenty to name. But something this widespread that scientists haven’t seen — “This is pretty unusual,” he says.