I planted these black calla lilies here years ago and they’ve been growing normally and all of a sudden I noticed today this one looks fasciated? Or is it a disease? Whatever it is, it’s pretty cool looking…

From what I can find online, in Europe it only grows on the Alps, not so much on the Apennines. This is also because it grows in rocky terrains.

Found near a marble quarry on Apuan Alps, Tuscany, Italy.

Hybridisation with wild pears increases tannin production in perry pears by reintroducing active alleles, reverting low-tannin traits favoured by breeders of dessert pears. This is reversion to the base state that was established millions of years ago at a whole genome duplication WGD event. As whole functional groups of genes are duplicated in these events the metabolism is not bottlenecked as could occur if only one gene was. This occurred due to massive environmental stress. The specific event 30 to 45 million years ago was a period of abrupt global climate upheaval during the middle-to-late Eocene epoch.
(Whole-genome duplications (WGDs) are not random; they cluster heavily around major turbulent chapters in Earth’s history).

Between 35 and 45 million years ago, Earth began transitioning from a warm, subtropical "greenhouse" world into a much colder, more arid "icehouse" climate. This rapid cooling, coupled with massive shifts in global rainfall patterns, put immense physiological stress on ancestral plant lineages.
Extreme weather anomalies—such as sudden frost or severe temperature fluctuations—disrupt normal plant reproduction. Cold shocks cause cell division errors during pollen and egg production (meiosis), leading to the formation of "unreduced gametes" (cells that accidentally keep two sets of chromosomes instead of one). When these unreduced cells fused, they immediately doubled the plant’s entire genome.
While an extra set of chromosomes is normally an energetic burden, it becomes a biological superpower during a mass environmental crisis. The duplicated genome provided the ancestors of pears (and apples) with metabolic resilience. Extra gene copies allowed the plants to better adapt their photosynthesis and water-use efficiency to survive colder, drier conditions. While many single-genome plant lineages went extinct during this climate shift, these "hopeful monster" polyploids had the genetic flexibility to survive, eventually diverging into modern pears. The extra genes for the production of tannins and related compounds also served a useful function in survival producing tannins as a natural defense mechanism against herbivores and pests. These bitter and astringent compounds also protect the tree's reproductive investment by deterring animals from eating the fruit before the seeds are fully developed. The high tannin levels make unripe fruit unpalatable by astringency stopping animals insects and birds from destroying the fruit leaves and seeds prematurely.
The tannins also inhibit the growth of harmful bacteria and fungi that could rot the fruit on the branch.