Autumn days aren't darker, in Kristi Mergenthaler's view, when hillsides around the Rogue Valley are ablaze in red, orange, yellow — even purple found at the heart of flames.
"The colors to me," Mergenthaler says, "are like a gift in exchange for the shorter day length."
Although most of the region's flowers have quietly expired, deciduous trees and shrubs are putting on the year's final display of color. And the fruits, seed pods and "architecture" of native plants offer plenty to see outdoors, says Mergenthaler, program coordinator for the Native Plant Society of Oregon's Siskiyou chapter.
"Southwest Oregon is exquisite in the fall with the mild temperatures, and the wind kind of clears the air quality."
The fall-color phenomenon happens when the chlorophyll in leaves starts to decay, revealing other pigments, such as carotenoids, which yield yellow and orange hues, says Mergenthaler, a botanist who surveys rare plants on public land. A plant's anthocyanins, she says, show up as red and purple. These chemical compounds act as "sunscreen" for plants, she adds.