Sedum palmeri by Marco Cristini
Erat enim instar ac si mundus ipse, excutiendo semet, reiecta hieme,
passim auream florum vestem indueret.
It was as if the world, shaking off the winter,
wore a golden dress of flowers in every direction.
(Rodolfus Glaber, Historiarum Libri, III, 13; slightly modified text )
Sedum palmeri Watson is a crassulacea of Mexican descent fairly widespread in Italy. It grows on the windowsills of houses and apartment buildings in many cities and it's able to survive outside during the colder months. Many people can see, around March, its yellow flowers, which indicate the ( long-awaited ) end of winter. However, few people know that it is a succulent plant, a relative of Sedum album and Sedum morganianum.
Sedum palmeri was described for the first time by the botanist S. Watson on the Proceedings of the American Academy of Arts in 1882. The name of this crassulacea remembers Edward Palmer (1829-1911), an American botanist who, in the course of the nineteenth century, led several scientific expeditions in Mexico. Today it is estimated that, during his explorations, he has collected approximately one hundred thousand specimens of plants and he has discovered a thousand new species. Also interested in archeology and Mexican culture, Palmer studied the way in which local people were using succulent plants, thus contributing to the birth of modern ethnobotany.
Returning to Sedum palmeri, this crassulacea grows in Mexico in the states of Coahuila, Guanajuato, Hidalgo, Nuevo Leon, San Luis Potosi and Tamaulipas (Garcia & Chavez, p. 63). Eggli (p. 304) writes that it is naturalized in Italy. Personally, I have seen sometimes S. palmeri growing in abandoned buildings or in abandoned gardens, but never far away from places where it had been intentionally introduced by humans. However, my observations are limited to Northern Italy: it is possible that in Southern Italy, considering the milder climate, the succulent has spread further from the most humanized places.