Missoula phlox can survive wintry wind blasts and midsummer droughts in the rocky scree on Waterworks Hill, but it cannot abide the trampling feet of off-trail hikers and their off-leash dogs.
So volunteers from Save Open Space and Missoula's Open Space Advisory Committee appealed to hikers Tuesday to help protect the rare cushion plant that inhabits the harshest habitat on Missoula's northern hills.
"It's a case of being loved to death," said Deborah Oberbillig, chairman of the Open Space Advisory Committee. "Waterworks Hill has become very popular, which is great. But people are spreading out on the trail and dogs are racing around, and the wildflowers are starting to suffer."
Thus the signs hammered into place by Oberbillig and others, warning of a "rare wildflower area ahead" on the path that takes hikers from a parking area off Greenough Drive to the peace sign - and through the cushion plant community.
In the rocky outcrop that rises up Waterworks Hill, Missoula phlox grows low to the ground and forms mats that bloom white and lavender in early to mid-summer. It is a subspecies of cushion plant found only in the Missoula area.
Also among the rocks are Douglasia, another subspecies of cushion plants that already is starting to bloom - pink and purple. Douglasia, too, is damaged by off-trail hikers and dogs.
Ecologist Mary Manning, who chairs the city's North Hills open space subcommittee, sounded the alarm after surveying the site earlier this year.
"The habit of these plants is to spread across the ground like a cushion," she said. "It's a strategy they use to conserve water and compete for resources. But it also makes them very susceptible to damage."
Missoula phlox and Douglasia are well-adapted to life in the wind-blasted environment high on Waterworks Hill. "It's an on-the-edge kind of deal," Manning said. "It's almost an alpine environment."
But they are still tiny, delicate plants.
Janet Sproull, president of Save Open Space, which holds a conservation easement on part of the property, said the plants are relatively easy to protect.
"If people will help us by staying on the trail and keeping their dogs with them as they walk through the phlox habitat, the problem will be solved."
Sproull hopes to make the trail a bit more distinct, so there is no confusion about where hikers should (and should not) tread. Several sections of fence, damaged by vandals, also will be fixed. And more signs will be installed.
"But we're really relying on people who use the area to take care," she said.
"These plants have all sorts of strategies for survival," Manning said. "But there's no strategy to protect them from people. We have to do that for them."