Final answer:
Exact descriptions by Pliny the Elder regarding the Campanian region are not provided in the resources given, but he wrote extensively on topics that would have included it, such as natural history and the customs of people.
Step-by-step explanation:
Pliny the Elder provided descriptions of various regions in his works, but specific details regarding his portrayal of the Campanian region are not explicitly provided in the references available. In his discussions, notably in the context of magic and its origins, Pliny discusses the spread of magic from Persia to other parts of the world, including the Gallic provinces, and even Britain. Pliny the Younger, his nephew, also wrote about the region, notably during the eruption of Vesuvius, offering descriptions of Vesuvius and the surrounding areas, but the elder Pliny's direct descriptions of Campania itself are not clearly outlined in the provided excerpts.
It is evident that Pliny the Elder wrote extensively on natural history, magic, and the customs of various regions, which would have likely included Campania given his comprehensive approach to documenting the world around him. Since the references did not provide direct quotes, we can infer that Pliny's depiction of the Campanian region would align with his interest in the natural world and human customs, possibly touching upon the region's fertility, prominence in the Roman world, and perhaps mentioning its susceptibility to natural disasters as reflected by the eruption that claimed his life.