The Yucca of Villa Malfitano

This is a yucca with a trunk five and a half metres round. Yuccas are the spiky things in pots by a doorway, and this one has gone woody and enormous in the garden of Villa Malfitano, which is what a Palermo climate and a hundred-odd undisturbed years will do to a plant that is technically not a tree at all. Botanically it is a monocot, closer kin to a grass or an agave than to an oak, and it has no annual rings, which is one reason nobody has put an age on it. The site already collects two dragon trees and several palms on the same logic: what matters is whether the thing is worth standing in front of. Its name is unsettled. The register files it as Yucca gigantea and the city's own description calls it Yucca australis, which are names that have been swapped back and forth for the same plant. If you know which is right, tell us. Villa Malfitano was built for the Whitakers, the English wine family who made Marsala and then spent the profits on Sicily, and the foundation that runs it charges entry to the house and garden both.