What's white, falls from the sky and marks the change of seasons in the Russian capital?
In winter--snow. In summer--"pookh."
Pookh is the fluff released by the blossoms of the poplar tree. As soon as the temperature changes in Moscow, waves of white come floating out of the sky, blowing past windows, drifting along sidewalks and piling up in doorways.
It's as if Mother Nature had a vicious sense of humor. Around here, snow lingers through the spring and can fall in May. And just as soon as the city finally seems to be rid of the cold white stuff, something that looks uncannily like it starts wafting through the air.
"You could say it's summer snow," Yulia Lebedeva, 20, said as she walked her 1-year-old daughter along a pookh-dusted sidewalk in central Moscow.
Pookh, which falls for a week or two but lingers on the ground well into summer, looks and acts so much like snow that it sometimes fools even those who have seen it before. U.S. scholar Kathleen Smith arrived in Moscow last week and was startled to see white blowing past her downtown hotel window.
"I called out to my husband--could it be snowing?" she said. "It didn't seem cold enough. But then I realized--it wasn't snow, it was pookh."
Most Moscow residents hate pookh, and not just because it reminds them of their winter scourge. It floats into eyes and up noses. It chokes drains and vents. It gets dirty, coats puddles and clogs grassy lawns.
And it's a fire hazard.
"It's like gunpowder--you hold a match to it for a split second, and the next thing you see is a burning path of fluff stretching meters away from you," said Yevgeny Bobylyov, a spokesman for the Moscow Fire Department.
Bobylyov said the number of fire alarms increases markedly in pookh season.
"It is very dangerous when children light it up for fun or adults throw around matches and cigarette butts," he said. "Unfortunately, kids do not realize how serious the danger is. Drunk adults are a problem too--intoxicated with alcohol, the thing they care about least of all is where they throw their cigarettes."
In fact, setting fire to the fluffy tinder is a favorite summer escapade. Two dentistry students, Oleg Zuyev and Evgeny Komarov, stood in their lab coats on a cigarette break and described the mischievous pleasure.
"You lay out a carpet of pookh, take a lighter and--'ssh!' Then, 'shhwwo!' " Zuyev said, making a large sweeping motion with his hand. "It's great."
"It's very beautiful," Komarov said. "You should try it. Of course, you have to make sure that there aren't any cars close by."
Many Muscovites blame pookh for the allergies that plague them in early summer--and the fact that the fluff tickles pedestrians' noses certainly enhances the effect. But Vyacheslav Treskunov, an allergist with the Moscow city health committee, insists that "pookh is totally harmless from the medical point of view."
"The problem is that the poplar fluff period coincides with the time when other plants of the grass family blossom," he said. "But it's so conspicuous that people who do not know about other grasses think that they are allergic to pookh."
Moscow's pookh problem can be traced to the devastation of World War II. After the war, Soviet dictator Josef Stalin ordered a tree-planting campaign to beautify the decimated capital.
Viktor Voskoboinikov, director of the city's plant and agriculture department, said poplars were a popular choice because they are hardy and grow especially quickly--as much as 5 feet a year, compared with just 20 inches for other species.
"But there was one thing that the city botanists overlooked. For some reason they forgot that there are two kinds of poplars--male and female," he said. "And it so happened that most of the poplars that were planted in Moscow were female--the ones that fill the streets with pookh every year.
"Apparently, in a country that had just emerged from the bloodiest of wars, it did not really matter much what poplar to plant--female or male."
Oddly, America is partly to blame for pookh. The poplar the Russians planted was an American variety, the balsam poplar, native to the northern United States and Canada. It was brought to Russia in the 19th century because it was hardier than European varieties. But it also produces more pookh.
Voskoboinikov warned that as the poplars age, a new hazard is looming--literally.
"An average poplar lives for 30 to 50 years," he said. "And since most of the trees were planted after the war, most of them are too old to even stand upright. Their core is rotten, and if there is a gust of wind, their huge branches tend to snap and fall down like stone boulders."
Voskoboinikov said it's time for Moscow to uproot the old poplars and plant new trees--as long as they are male.
But for the most part, Muscovites seem resigned to their summer snow. After all, in a country with too much winter, pookh is a small price to pay for a few months of summer.
Pookh, said 22-year-old Yekaterina Daronina, means "good weather, warm weather."
Alexei Kuznetsov and Rachel Nielsen in The Times' Moscow Bureau contributed to this report.