1. Drain oranges, reserving 1/4 cup liquid. Combine reserved liquid and gelatin in a small saucepan; let stand 1 minute. Stir in lemonade concentrate. Bring to a boil, and cook 2 minutes or until gelatin dissolves, stirring constantly.
2. Remove from heat, and stir in poppy seeds. Cover and chill 3 hours or until mixture is thickened.
3. Combine oranges, cherries, peaches, and plums; toss gently. Pour lemonade mixture over fruit mixture, and toss gently.