Bring 6 quarts of water to a boil in a large saucepan over high heat. Add 2 tablespoons salt and return to a boil. Add spaghetti and cook according to package direction, until tender but still al dente.
Heat olive oil in a 12-to-14-inch skillet over medium-high heat. Add root ends from ramps to pan and cook, stirring, until tender. Season with red pepper flakes and salt. Add leafy greens from ramps and cook, stirring, until wilted.
Drain pasta and add to skillet. Toss gently to coat pasta with sauce. Divide pasta evenly between 4 warmed plates. Drizzle with olive oil and sprinkle with breadcrumbs. Serve immediately.