Vibrant green with lustrous leaves in the Spring, Poison Oak (Toxicodendron diversilobum) generally becomes less vivid with age, eventually turning red in the late Summer and Fall. The red color is due to anthocyanin pigments in the plant's sap that become unmasked as the leaf loses chlorophyll.

Brown seed stalks of Curly Dock (Rumex crispus) amid dried grasses and mustard on Laskey Mesa in Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch).

Curly dock is a non-native invasive weed from Eurasia. The Cal-IPC Invasive Plant Inventory describes its impact as limited.

From a run at Ahmanson on September 13, 2006.

Sylvan Hairstreak (Satyrium sylvinus) on California Goldenrod (Solidago californica) at Sage Ranch Park.

A Southern Pacific Rattlesnake (Crotalus oreganus helleri) at Upper Las Virgenes Canyon Open Space Preserve (formerly Ahmanson Ranch).

Photograph of Foxtail Pine from the Cottonwood - New Army Pass Loop September 2, 2006.

The climb up the glacially sculpted canyon hadn't been too bad. How could it be on a day like this? Winds were light, and the temperature was refreshingly cool – perfect for running in shorts and a lightweight long-sleeve top. As I had worked up the Rock Creek trail, marmots, fat for the Winter, had whistled warnings of my approach and then waddled for cover. Amicable clouds embellished the high mountain sky, and sun-chased shadows quietly set the pace.