Spaghetti with Squash Blossom Butter and Summer Beans

Name: Spaghetti with Squash Blossom Butter and Summer Beans
Ingredients: 4 tablespoons unsalted butter, at room temperature; 9 squash blossoms, stems and pistils removed and petals finely chopped (1/2 cup), plus whole petals for garnish; 8 ounces green beans, trimmed; 6 ounces wax beans, trimmed; 1/2 pound spaghetti; 1/4 cup snipped chives; 2 tablespoons chopped basil leaves, plus small leaves for garnish; 2 tablespoons finely grated Pecorino Toscano or Romano cheese, plus more for serving; 1/2 teaspoon finely grated lemon zestplus 1 tablespoon fresh lemon juice; Kosher salt; Pepper