People who live in the St. George Basin of southwestern Utah like to brag they see God's handiwork at every turn. If that be the case, then God has woven a most-unusual biological quilt.
"With the convergence of the the Mojave Desert, Great Basin and Colorado Plateau, we have unique species not found anywhere else," said Reed Harris, Utah field director for the U.S. Fish and Wildlife Service. "And whenever development starts up, then it starts putting pressure on populations that were never very large in the first place."On Wednesday, the Fish and Wildlife Service proposed adding two plant species -- the Holmgren milk-vetch and the Shivwits milk-vetch -- to the list of federal protected endangered species. Both are found only along the Utah-Arizona border.
The remaining populations of both species are very small. Botanists estimate there are 5,000 to 11,000 Holmgren milk-vetch plants surviving in Washington County, Utah, and Mojave County, Ariz. Only about 1,000 Shivwits milk-vetch plants are known, all in southern Washington County.
The numbers of both plants have been steadily diminishing because of rapid urban expansion and associated road construction that has destroyed much of the plants' habitat. Other factors that have contributed to the plants' demise has been livestock grazing, off-road vehicles, the spread of weeds and mineral development.
"These plants are a unique part of the natural heritage of the Southwest," said Ralph Morgenweck, regional director for the Fish and Wildlife Service. "Listing them under the (Endangered Species) Act will provide not only for their protection but also for their long-term recovery."
Those sentiments were echoed by Page Wolken, a Fish and Wildlife Service botanist who has worked with the endangered plants. "They are especially valuable because they are so rare and unique," she said.
Most of the land where the milk-vetch is found is managed by the Bureau of Land Management, although some plants are found on Paiute Indian lands and on private lands subject to development. Federal officials are currently fencing off five different "native plant areas" with milk-vetches that are considered to be most threatened.
"What the listing does is give us the opportunity to prepare a recovery plan and establish recovery goals," Harris said. "Right now, we still don't know how many (more plants) it would take to get them off the endangered species list."
The Holmgren milk-vetch grows along the ground, spreading in a circle of leaves with tiny, oval-shaped leaflets. They are found in shallow, sparsely vegetated soils, and they produce small purple flowers in the spring.
The Shivwits milk-vetch grows 8 to 20 inches tall and has flowering stems that can be up to 40 inches tall. These plants are found in clay soils and produce cream-colored flowers favored by most wild and domestic grazing animals.
The proposal to list the two plant species as endangered was published Wednesday in the Federal Register. Comments must be received no later than June 11 at the U.S. Fish and Wildlife Service, Lincoln Plaza, Suite 404, 145 E. 1300 South, Salt Lake City, UT 84115.
Other endangered species in the Washington County area include the Bearclaw poppy, Desert tortoise, Virgin River woundfin and chub, Southwestern willow flycatcher and bald eagle.
Harris said the listing comes as no surprise to Washington County and state officials. Both species were identified as candidates for listing during ongoing efforts to recover the endangered Desert tortoise, and since that time "We have talked with most of the people down there who are affected by the decision," he said.
You can reach Jerry D. Spangler by e-mail at spang@desnews.com.