May 6 on The Story: In the Johnson Creek Watershed, deep in Southeast Portland, the forest understory is full of green, leafy stalks topped with small white flowers. They may look right at home, but these herbs — known as garlic mustard — are an unwelcome invader in North America, and they've been making inroads to the Pacific Northwest for decades. Luckily, groups of conservationists have been working nonstop for years to control the spread. But failure could be harmful to the health of Oregon's native plants, and all of the wildlife that depends on them. Watch more The Story videos: http://bit.ly/watchTheStory Follow The Story on Twitter: https://twitter.com/TheStoryKGW Follow The Story on Instagram: https://instagram.com/thestorykgw