Category: StreetSmartNaturalist

Plants and Stone: The Colosseum

One of my favorite little books about building stone was published in 1855. The author, an erudite English chap named Richard Deakin, turned his attention to the Colosseum, which he called “the most remarkable, the grandest, and the most imposing of all the vast ruins of Ancient Rome.” Deakin reveled in the “noble and graceful animals” who tore “each other to pieces,” and who also made meals of “numberless human beings.” But his real focus was on the plants that had taken over the great structure. In The Flora of the Colosseum, he described 420 species.

For better or worse, the modern Colosseum is a cleaned and sanitized version of its historic past. Gone are the plants that once made the building basically a big nursery. For hundreds of years, flowers, shrubs, and trees sprouted from the travertine and tuff walls. The first list appeared in 1643 and included 336 species, although this historic list does not correspond well with modern names. A study in 1815 dropped the number to 260 but then came Deakin, who appears to have combed every square foot of the Colosseum.

One of Deakin’s 420. From Smithsonian Institution Library web site.

Filled with wonderful drawings, the book is also a delight to read. Like the best interpretive writing, Deakin delves into history and science, giving each plant a story, and something for the inquisitive botanist to discover. For example, said plant lover could find cures for dysentery, gout, and rheumatism, dine on strawberries, lettuce, onions, and asparagus, and alleviate the effects of “too great potations” of wine. If you are interested in testing Deakin’s hangover cure, all you have to do is find some Hedera helix, better known as English ivy.

Alas, archaeologists in the 1870s recognized how damaging plants were to the structure and stripped the green mantle. Diversity also decreased with the loss of grazing animals and their contributions to soil fertility. Not all plants have fared poorly in modern times: the most recent floristic study, conducted in 2002, reported that alien species, particularly those associated with humans, have flourished. The 2002 study described 242 species, and total diversity for all studies is 684 species.

Although I understand why workers in Rome remove the plants, I wish they didn’t have to. At least the plants grow fast enough that I can still see this wonderful link between geology and botany.

Cobblestones Again: Europe

Several weeks ago, my blog about Seattle cobblestones generated a bit of interest so I thought I would follow up by discussing a few old cobblestone roads from Europe. I am using the term cobble a bit loosely, as technically it refers to a stone ranging in size between 64 and 256 millimeters. Furthermore, cobbles typically are rounded due to ice or water. In this context, a cobble is a stone used as a paving material.

My favorite are the gray cobbles used throughout Rome. Locals call the three-inch-square paving blocks, “San Pietrini,” little Saint Peters, playing on St. Peter’s role as the rock of Christianity. In his landmark De Architectura, or The Ten Books of Architecture, Vitruvius referred to the lava that made the stones as hard, enduring rock, calling it siliceae, or silex.

San Pietrini in La Piazza del Popolo, Rome

More exotic cobbles are found in Seravezza, one of the great localities for marble in Italy. It was here around 1519 that Michelangelo went in search of white marble for the façade he had designed for the church of San Lorenzo in Florence. The church was never built but Michelangelo did open up quarries still used at present. In the sidewalks of Seravezza, you can find a wide variety of the many colors of marble quarried in the Apuan Alps.

Marble paving stones of Seravezza

In the town of Volterra, about 30 miles southwest of Florence, are massive paving stones. Volterra is a classic Tuscan hill town with a history that stretches back to Etruscan times. The Etruscans built several gates, one of which remains and still has figures carved out of basalt, though much weathered. The well-worn roads are made of sediments rich in fossil shells, the largest of which are the size of a deck of cards.

Shells in the road of Volterra

I have not visited my final site of European cobbles. I learned about it from Michael Welland, who writes the blog, Through the Sandglass. Here is what he had to say about the old French Mediterranean city of Narbonne. “Awe-inspiring, the oldest cobbles are the pavement of the great road of the Roman Empire (Narbonne was a major regional capital), the Via Domitia. This section of the road was uncovered not that long ago in the town square. This is really hairs-on-the-back-of-your-neck stuff as you gaze at the wear of traffic 2000 years ago.” He thought they were highly indurated marbles.

Via Domitia (photo courtesy of Michael Welland)