Sixteen plants that eke out an existence on the Channel Islands and nowhere else on Earth may become the newest additions to the nation's list of 759 endangered species of plants and animals.

With such obscure names as fringepod, munchkin dudleya, alumroot and bush-mallow, the plants will not be missed in most households if they become extinct.

But the dwindling populations of those shrubs, succulents and herbs on the wind-swept islands off the Ventura County coast are irreplaceable links in the island ecosystems, said Connie Rutherford, botanist with the U. S. Fish & Wildlife Service in Ventura.

"The islands represent this whole complex web of interactions among plants, animals, soil and hydrology, all working together," she said. "When we start removing pieces one by one, at some point, the whole system fails."

In addition, she said, those plants, many of which are on Channel Islands National Park lands, are part of the nation's heritage.

"And the national parks are supposed to maintain that heritage for the public," she said.

The 16 plants, some with tiny pink or yellow flowers only half an inch across, were proposed for listing by the Fish & Wildlife Service's Ventura office under the Endangered Species Act as a means of protecting their remaining populations. They are found on Santa Rosa, Anacapa, Santa Cruz and San Miguel islands.

Three more plants found on Catalina or San Clemente islands farther south were proposed for listing at the same time by the service's Carlsbad office.

Five of the plants have only one population, or one cluster, where they exist. Most of the others have fewer than 10 populations. One--the island alumroot--has 27 populations.

The proposed listings are part of a settlement of lawsuits brought by the California Native Plant Society and the Fund for Animals that challenged the Fish & Wildlife Service's timeline for listing 160 plants in California and more across the nation.

The proposals, which are out for public and peer review, would normally become final one year after being published in the Federal Register. In this case, the listing would become final July 25, 1996.

But a congressional moratorium on final listings may hold that process up, Rutherford said. Nevertheless, even the proposal for listing lends the plants a measure of protection under the Endangered Species Act.