The Blackberry vine shown in this photo is a common understory plant in Pacific Northwest forests. Where it gets enough sun, it has small white flowers. It seems to seldom set fruit. The vines are about an 1/8" to 3/16" in diameter. Like most caneberries, it spreads by tip-rooting.
Ash Creek Images
Photographs of the West by Doug Gorsline
Hairy Spines on a Native Cascade Blackberry Leaf Glisten with Frost.
