Schmoll's milk vetch, for instance, occurs nowhere else in the world except Mesa Verde National Park, in southwest Colorado, and it simply didn't appear this year. "I was supposed to go to the park and map the area where the plant is located," Anderson says. "But the park service called and said don't bother."
At the famed wildflower festival in Crested Butte last month, first-time visitors were excited, as usual, but longtime organizers could tell this year wasn't normal.
"Very dry," says Lee Renfro, festival director. "You have to promise yourself that, yes, they're there, and they will come up next year."
Bonebrake presses higher and higher, until at last he spies something purple sprouting from a rock. He stops. He gathers his gear and stalks toward the asters, as if any sudden movements might scare the flowers off.