Toss beets in oil with salt and pepper; roast (covered) in a 350 degree F oven 20-30 minutes, or until beets are tender. Once cooked, place beets in refrigerator until cooled. Peel skin with paring knife, then slice beets.
In small mixing bowl, toss beets, orange segments, vinegar, sugar, and pepitas. Season to taste with salt and pepper. Garnish with edible flower petals. Serve.