Asplenium ceterach – Rustyback Fern

Left: Asplenium cetarach botanical drawing (www.biolib.de).
Center and right: Photos of Asplenium cetarach on a wall in Bergamo.

The upside of the coronavirus lockdown (November 2020 edition) is that we've spent more time walking and exploring parts of Bergamo we usually don't. Case in point, we found ourselves on the Scaletta Scorlazzino, a beautiful and long stair climb up the southern slopes below Via Sudorno. On these sun-exposed walls we ran into Asplenium ceterach, commonly known as the Rustyback fern, another good candidate for a "wall plants of Bergamo" post.

Unlike many other ferns, A. ceterach likes sun and requires little humidity. The Rustyback fern is also known "as a resurrection plant due to its ability to withstand desiccation and subsequently recover on rewetting."[ref] That's an apt metaphor for the on and off again lockdowns and looking forward to getting through this pandemic intact.

The family Aspleniaceae (recall the taxonomy: kingdom, clade, class, order, suborder, family, genus, species) is a family of ferns called spleenworts for their approximate resemblance to spleens. In two previous posts we talked about two other wall-loving ferns in this family: Asplenium ruta-muraria and Asplenium tichomanes, that both look similar to A. ceterach.

Rustyback is found in Western and Central Europe, including the Mediterranean region. It is commonly found growing in fissures in limestone and dolomite rock and on the mortar of stone and brick walls, as in these photos. The English common name Rustyback – according to Wikipedia – is due to the orange-brown hairs (trichomes) on the backside of the fronds.

In Italian, this fern is called la cedracca. According to Treccani, this Italian word derives ultimately from the Persian word shītarak.

Left: A photo of Asplenium cetarach on a sunny wall of the Scaletta Scorlazzino in Bergamo.

Right: The underside of the an A. cetarach frond.

Asplenium ruta-muraria – Wall Rue

Left: Botanical illustration of Asplenium ruta-muraria.
Center and right: Asplenium ruta-muraria on a wall in La Rocca, Bergamo.

Today we spent an hour visiting La Rocca – a fortress that is part of Bergamo’s Città Alta. La Rocca fortress is made up of a memorial park and the Casa dei Bombardieri or Bombardier’s School. The park is free to enter and explore, offering 360-degree views and a great view on to Città Alta as La Rocca is at the east edge of the upper city. The school is the main building in La Rocca and contains one of the museums in the family of Bergamo museums called Museo delle Storie di Bergamo, and even better 360-degree views.

The museum inside La Rocca, also called Museo dell’Ottocento, deals with the Risorgimento (Italian Unification) and while it is a difficult museum to get through it is one of the most rewarding for those that persist. Part of the difficulty is the subject matter. The Risorgimento had many players and events that are hard to keep track of. Also, this museum is currently all signed in Italian, and the exhibits are on complex subjects such as the silk economy, an overview of the Fiera (a very important fair that once existed in the lower city), and demographic and economic facts and figures.

Included in the museum entrance fee is access to access to the top of the Casa dei Bombardieri. On the stairs up to the top of the roof, we noticed this fern that looked similar but not exactly the same as the Maidenhair Spleenwort we talked about in the post Asplenium trichomanes – Another Bergamo Wall Plant.


The plant we noticed is in the same genus and is called Asplenium ruta-muraria, commonly known wall rue. First, based on our obsessive analysis of walls in Bergamo, A. ruta-muraria seems to be much less common than A. trichomanes. Second, A. ruta-muraria has green rachises (midribs), not black like A. trichomanes. And, A. ruta-muraria has pinnules that look like small ginkgo leaves or as suggested by the common name, like the leaves of Ruta graveolens, commonly called rue.


Wall rue is a lithophyte, that is, it grows in or on rocks, and grows exclusively on limestone and other calcareous rocks. In Europe and cities like Bergamo, it can be found on masonry works. Wall rue is called ruta di muro in Italian and according to Flora Italiana (one of our go-to sites), it is present all over Italy. Wall rue is present in the Eastern United States as well but is found more in well-weathered limestone outcrops and rarely invading masonry works according to Flora of North America.

Left: The sori (spore structures) of Asplenium ruta-muraria.

Center and right: More examples of A. ruta-muraria on walls in Bergamo.

Asplenium trichomanes – Another Bergamo Wall Plant

Left: Asplenium trichomanes botanical drawing (www.biolib.de).
Center: Asplenium trichomanes in a wall on Via Tassis in the Upper City of Bergamo.
Right: The spore containing structures (sori) of Aspleninum trichomanes.

We admit it: we are thinking about walls a lot these days. We live in a walled city whose fame rests on having 6.2 km of massive walls surrounding its upper city, Città Alta. Those walls were built by the Venetians in the 16th century. Almost daily, we are walking on and through Bergamo's Venetian walls.

Once inside the upper city, there are a maze of streets that lead you to the Piazza Vecchia, and all of them involve navigating between walls of various types. And lucky for us, interesting plants grow on walls so we are never bored. In the past, we posted about such plants: The Flower that Grows on Walls - Cymbalaria muralis, Pennywort and Pellitory of the Wall (Parietaria judaica). We are back this time with another wort plant, this time Maidenhair spleenwort.

Wort is an ancient English term that simply means "plant". When put together with the name of a part of the body – spleen in this case – it generally meant that the plant was thought to cure problems with that body part. In the case of Maidenhair spleenwort, the sori on the back of the fronds are spleen shaped. 

The wort naming of plants is part of the doctrine of signatures, today considered pseudoscience. Other plant examples with wort in their common name include lungwort, woundwort, toothwort, and liverwort.

Maidenhair spleenwort, Asplenium trichomanes, is a small fern in the the genus Asplenium. On first glance, it looks like what is commonly called a maidenhair fern (genus Adiantum) but that’s in the family Pteridaceae. The spleenwort is however in the same genus as the bird's-nest ferns (A. nidus) commonly sold as house plants. For Maidenhair spleenwort, you must content yourself with finding some walls to enjoy them, and all the better if they are walls in an Italian city like Bergamo.




Left: Maidenhair spleenwort in the botanical garden of Bergamo.
Center and right: Maidenhair spleenwort on Via Noca, Bergamo.

Examples of Asplenium trichomanes - Maidenhair spleenwort.