The giant panda, which had been making a modest comeback from its endangered status, is suddenly facing its worst food crisis in years, Chinese wildlife experts say.

Officials in the southwest province of Sichuan, where almost all of the world's 1,000 remaining pandas live, report an unexpected and widespread flowering of the cuddly creature's staple--arrow bamboo. The plant blossoms once every few decades, then withers and dies.

Pandas in five of the province's eight protected zones are foraging the mountainous terrain for food, and some have begun eating grass, a poor substitute that causes diarrhea, according to reports.

The last time bamboo bloomed in Sichuan in the mid-1970s, 138 pandas--then more than 10 percent of their total population--starved to death.

Chinese and western wildlife officials say the bamboo shortage could become a "real emergency" in the next cold season.

China's government, which prides itself on supplying the world's zoos with the beloved, bear-like animals, has responded to the crisis with unusual dispatch. A "panda emergency action group" has been set up and funded with $150,000 to find a remedy to the bamboo blight.

The panda's picky eating habits rule out easy solutions. A hungry panda, for example, will often just get hungrier, then become too weak to find bamboo brought by man.

"When they are starving, they do not not even have the strength to reach the food," said conservationist Ma Xingmian.

So, experts have resolved to bring the pandas to the food. There now are plans to round them up, put them in special farms and keep their bellies filled with choice bamboo, consumed at a tremendous rate.

Another plan is to transport pandas to places where arrow bamboo is plentiful and in no danger of flowering in the near future.

Until the recent scare, the panda had seemed to be holding its own. After years of field research in Sichuan, specialists concluded in 1981 that the panda population had begun stabilizing in the conducive environs of China's southwest.

World Wildlife Fund officials and Chinese scientists at Sichuan's Wolong nature reserve have been studying the eating and mating habits of the mammal, whose history dates back at least 500,000 years, in hopes of preventing it from going the way of the dinosaur.

According to recent reports from London, however, the panda is facing a threat larger than natural selection.

The Sunday Times reported that skins of pandas, killed to order, are being sold on the international black market for as much as $26,700. The newspaper said the skins are being offered by a Taiwan trader.

According to the article, the fur finds its way to the black market through Hong Kong, which serves as a conduit for indirect trade between Taiwan and the mainland.

[The president of a Taiwan trading firm Wednesday denied the report in the Times that his company is selling the panda skins, The Associated Press reported.]