Saidi Mwile's face lights up as he squats down to examine an orchid on the Kitulo Plateau of this east African nation.
But his delight is not in the brilliant red flower. He's imagining the delicious taste of its root.
"When it's cooked, it tastes very nice, a lot like liver," Mwile said, carefully slicing off the tuber, which resembles a tiny potato.
For generations, people on this high, chilly plateau known as the "Serengeti of Flowers" have been harvesting the tubers of terrestrial orchids. Then they dry, pound and boil the resulting flour with wood ash to prepare "kinaka," an orchidean sausage that is a prized local delicacy.
But a burgeoning -- and illegal -- export trade in tubers to gourmets in neighboring Zambia is threatening the plateau's remarkable orchid population.
Between 2.2 million and 4.1 million tubers of dozens of species of terrestrial orchids are harvested every year for export to Zambia, said Tim Davenport, a field biologist with the Wildlife Conservation Society.
The society has set up the Southern Highlands Conservation Program in Mbeya, 420 miles southwest of the capital, Dar es Salaam, to protect important upland habitats and species in southwestern Tanzania.
"The problem is growing. The demand in Zambia seems to be so high that people are now willing to move anywhere. ... conservation is now very difficult," Davenport said.
The Kitulo Plateau is not just home to orchids. For six months of the year, it is covered with other spectacular wildflowers and is home to many species of birds, including the blue sparrow.
One solution would be to make the 52-square-mile area a national park, the first in tropical Africa aimed specifically at protecting endangered flora.
Davenport and Henry Ndangalasi, a botanist at the University of Dar es Salaam, have been studying the orchids for two years. They warn that orchid-collecting is growing so fast that it likely will not be sustainable.
Orchids are protected under the Convention on International Trade in Endangered Species of Wild Fauna and Flora, CITES, which requires certification of plants taken across international borders.
But Mwile, a 41-year-old farm worker, has never heard of CITES and doesn't know that orchids are protected. Like others on the plateau, he looks forward to the harvest, which gets under way about this time of year.
Solomon Mtwebe, who works with the Wildlife Conservation Society to inform locals about the dangers of over-harvesting, says collectors now burn off the plateau grass so that the orchids shoot up quickly and can be easily harvested.
"They dig them up and sell to me," said Eliath Sangah, a middleman who packs the tubers in 220-pound sacks and transports them to the border town of Tunduma 75 miles away.
He buys 44-pound plastic buckets full of tubers for about $1.50 apiece, then sells them in Tunduma for about $5 to $6.
"It's a better business than selling potatoes," said Sangah, 30, who looks much better off than the harvesters, who are clad in rags.
"It's not true that orchids are getting finished," he said. "There are many other buyers who started trading in 1983 -- when exports began -- and who are still in business."
But the harvesters know there is a problem. These days, it takes them three days to fill a bucket; two years ago, it took a day.
"It is now a very tough job. I do it because I need money," Pascal Kiondu said. "We don't have to buy the tubers, and it's better to be digging up orchids than to be idle or stealing."
A year ago, President Benjamin Mkapa declared that the Kitulo Plateau -- which the Wildlife Conservation Society says hosts "a staggering diversity of orchids" -- would become a national park. But the nation's parliament has not yet approved the declaration.