The sculptor Giuseppe Penone, a pioneer of Italy’s Arte Povera movement, is known for his stripped and skeletal trees in copper, stone, and wire, and his explorations with rocks and bark. His practice is rooted in the natural world. Though the Galleria Borghese is known for its extensive Renaissance collection, it is making an exception for the Turin-based contemporary artist, whose organic works in bronze, wood, and leather will be installed in the galleries and gardens, in whispering dialogue with the palace’s archways, affreschi, and works in marble. —Elena Clavarino