Possible Clues:

• Ornamental garden plant — holding one, state politicians squeal
• Father and son crossing first of many treeless plains
• South American grasslands
• Father’s banked millions, that’s plain
• Dad's traversing peak of Moroccan plains
• S American grass
• Treeless plains of South America
• Plain fool with plan drawn up
• Mug's plan to go over grassy plains
• Old man's covering miles in vast plains