Ruderal Plants: The Otherworldly Flora of the Colosseum and Chernobyl


“Sometimes the best thing you can do is…. nothing. –Oliver Kellhammer, Ecological Artist 

There’s a lesser-known field of botany called the study of ruderal plants, or plants that grow on waste ground, ruins or rubble. Borne by birds, wind or other animals, the weed-like species are the first plants to colonize lands disturbed by wildfires, avalanches, construction and other ecological disasters. Self-sowing in abandoned areas, the hardy plants take root, demonstrating what Mother Nature will create when left to her own devices.


I’ve always been fascinated by this area of study that attempts to understand how these unusual plants came to be. Back in 1643, the Roman botanist Domenico Panaroli (1587-1657) was interested, too, when he began compiling the world’s first inventory of plants growing in the ruins of Rome’s Colosseum. Of the many species he observed flourishing in and around the stone arena, he noted that most originated not in Italy, but in North Africa.

In his book titled Flora of the ColosseumPlantarum Amphytheatralium Catalogus, Panaroli identified 337 ruderal plants growing in the diverse microclimates of the 6-acre Colosseum. The lush vegetation, which was thriving without apparent need for cultivation, exhibited a dynamic interplay between native and non-native species. The surprising findings led Panaroli to hypothesize that the exotic plants had traveled in with birds, or by wind or possibly on the coats of animals brought to fight in the ancient Colosseum.


Photo credit: SF Photo/

Two hundred years later, an English doctor named Richard Deakin recorded 420 species growing simultaneously in the ruins. The plants, which he documented in his 1855 book Flora of the Colosseum of Rome, included figs and vines, wild roses, orchids and dianthus, many of which had naturalized in the many atmospheric zones of the ancient forum. He wrote:

The object of the present little volume is to call the attention of the lover of the works of creation to those floral productions which flourish, in triumph, upon the ruins of a single building. [ ] Though without speech, they tell of that regenerating power which reanimates the dust of mouldering greatness.


Today the list of species from the Colosseum has grown to 684. Of these, over two hundred of the species first identified by Panaroli still remain.



In our lifetime, or at least mine, one of the largest ecological disasters occurred in 1986 in Ukraine when an explosion and fire in the Chernobyl nuclear plant released large quantities of radioactive particles into the atmosphere. The catastrophic nuclear disaster contaminated hundreds of square kilometers in the areas of Ukraine, Belarus and Russia in the former USSR.

During the first decade following the accident, though, scientists began observing an important change in the make-up of the area’s microscopic organisms. Following their exposure to high levels of radioactive contamination, the bacteria had started mutating more rapidly to form new radiation-proof life forms.


Former amusement park near Chernobyl

The worst-affected woodland, composed primarily of Scots pines, is today known as the Red Forest. (The name comes from the ginger-brown color the trees assumed after absorbing the intense doses of radiation.) Although the majority of the pines were bulldozed and buried in trenches, today scientists are observing what they term an ‘unnatural selection.’ Ruderal plants are growing in the woodlands and their biodiversity is increasing. In the last ten years, the M.G. Kholodny Botanical Institute of NAS of Ukraine has recorded intensive processes of reforestation as well as the presence of more than 40 different trees that have begun appearing in the Red Forest. These include some entirely new species.


The black locust, is one of just many plants that are growing in the Chernobyl area.

Undisturbed by humans, aggressive ecologies of native species, including several new kinds of natural lichen and grasses, have developed. As they commingle with other exotic groups, the ruderal plants are combining to form species that have never before been envisioned. Some of the plants and animals have evolved a tendency to produce more cancer-fighting antioxidants to help them resist the effects of pervasive radiation: attributes that may one day help humans develop their own.


Oliver Kellhammer  is an artist, educator, activist and writer. Through his botanical interventions and public art projects, he seeks to demonstrate nature’s surprising ability to recover from ecological damage. His evolving body of work has taken such forms as small-scale urban eco-forestry, inner city community agriculture and the restoration of eroded railway ravines.


Concrete Island by Oliver Kellhammer

In 2006, Kellhammer created a ruderal botanical garden for the World Urban Forum, which was held in a former heavy equipment plant in Vancouver, British Columbia. For his installation, he found a disused corner of the site, a concrete rectangle, where a variety of weeds and other plants seemed to be flourishing. Rubble, garbage and other debris had provided the perfect conditions for ruderal plants such as Scotch broom, Cottonwood and Himalayan Blackberry as well as several species of mosses and grasses to grow.

Kellhammer noted that the plants comprised both native and non-native species; a reflection of sorts of the city’s Asian, European and native British Columbian inhabitants. To call attention to the plants, he installed botanical labels on various species with the option to push on a button to connect visitors’ cell phones to recorded information. The Concrete Garden provided interesting insights into the workings of ruderal plants as well nature’s incredible resiliency.

Yes, Mother Nature is full of surprises. One has only to look to the Colosseum, Chernobyl and innumerable abandoned areas around the world to see the processes of her regeneration, proving that architecture, like we, is inevitably ephemeral.



2 thoughts on “Ruderal Plants: The Otherworldly Flora of the Colosseum and Chernobyl

  1. Interesting post, but I am curious as to your definition of the term Ruderal plant. The word comes from the Latin “Rudus” which means rubble and that seems to be the way you are using it as any type of plant which volunteers within any and all ruins.

    I’ve always used it to describe non-mycorrhizal rooted plants like weedy annuals which thrive in a bacterial system with high nutrient content as opposed to a mycorrhizal one where the fungi with prevent weeds from overwhelming the system. For example I’d never consider Black _Locust as Ruderal under my definition, but would be ruderal under the general description of volunteering within the rubble of ruins.

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