Endangered species pop up in the strangest places. Like flowerbeds. Plant-protection activists say some species of bulbs bought to decorate American and European gardens are being collected by the millions in the wild, threatening to wipe out those flowers in their home turf. ``The world would lose an irreplaceable treasure,'' said Marjorie Arundel of Warrenton, Va., an adviser to the Garden Club of America's horticulture committee. ``They're the ancestors of all of our spring bulbs today.'' Mrs. Arundel and other activists are urging American gardeners to buy only commercially propagated plants, which experts say make up at least 99 percent of the flower trade anyway. ``Wild-collected flowers are a small percentage of the trade, but a large percentage of certain kinds of plants,'' said Faith Campbell, director of the plant conservation program for the Natural Resources Defense Council, an environmental group. Working with the World Wildlife Fund and the Garden Club of America, the NRDC has produced leaflets calling on gardeners to avoid most kinds of cyclamen, sternbergia and galanthus, or snowdrops, which they say are collected in the wild in Turkey. Those three species are listed as endangered in the Convention on International Trade in Endangered Species of Wild Fauna and Flora, or CITES. But this treaty _ effective in fighting trade in some endangered animal skins, horns and tusks _ has had little effect on the flower trade, Ms. Campbell said. Snowdrops are greatly depleted in Turkey's Mediterranean regions, forcing traders to seek out sources in more remote regions. The popular ``Angel's Tears'' narcissus are being collected in the wild, but experts are not sure if the source is Portugal or somewhere else. Other wildflowers, such as trillium, are being collected from the wild in the United States and Canada. Japan, China, India and the Soviet Union appear to be the sources for still other rare flowers. Some species of these plants may be produced by growers in the United States or Europe, but buyers are being counseled to check the origins as carefully as they can. This may become easier, as a result of the decision last May by the Dutch Commodity Board for Ornamental Horticultural Products to require exporters to use a ``Bulbs from Wild Sources'' label to identify wild-collected plants. Under the negotiated agreement, Dutch exporters will also label their cultivated bulbs, beginning in 1992 for minor species and in 1995 for such major bulb varieties as tulips and hyacinths. Because the Netherlands has long dominated the world flower trade, the action by the Dutch regulatory body should have a major impact, Ms. Campbell said. It is not binding, though, on dealers in the United States or other countries. Also, the agreement was reached too late for most of this fall's catalogs. So even if American gardeners order from Dutch dealers covered by the rules, they might not know they were buying wild-collected flowers until the bulbs arrive in the mail, labeled ``wild sources.'' ``We can just hope they won't order those again,'' Ms. Campbell said. ``It is a messy phasing-in.'' The long-range solution, she said, could be in helping people in Turkey and elsewhere who make money from collecting wild flowers to start propagating the rare flowers in or near the native habitat, she said. Gardeners shouldn't think they're aiding nature by keeping alive a species that might be disappearing in its native habitat. ``We don't consider that a contribution to conservation in any way,'' Ms. Campbell said. ``It's not playing its role in the ecosystem in which it evolved.''