Identifying marine algae in the wild isn’t always easy – hardly ever easy. The filamentous greens are a good example. The field guides do their best, but the the greens are tough for a non-expert like me. There are plenty of common browns and reds that are hard to identify too. Still, I can’t resist trying to name all the algae I encounter. My list keeps growing because the more I learn, the more I see. All this effort at naming isn’t mere collecting or listing. Learning to identify helps me communicate and understand connections, and mostly, it’s fun. I’ve done my best in the pages that follow to show some useful photos of the commonest, most obvious intertidal algae. I make no promises that the IDs I propose are correct. If you see a mistake or an out-of-date usage, I hope you’ll let me know. I’ve split my treatment into separate pages for greens, browns, and reds. Click on the links and you’ll find are examples of common algae I encounter from shore on the exposed outer coast of northern Oregon.