Botanical Accuracy: Frosty fern? It is a variegated spike moss

Friday, January 10, 2014

Frosty fern? It is a variegated spike moss

Before Christmas a fern-looking plant often shows up in the supermarkets and is marketed as 'frosty fern', a name it gets from its fern-like leaves (more on that later) and white-tipped branches.

'Frosty fern' for sale, with rather zoologically inaccurate cardinals as highlights, but that is for another blog.
Photo (cc) BotanicalAccuracy.com.

Frosty fern for sale at Shoprite in New Jersey, USA.
Photo (cc) BotanicalAccuracy.com

But, in fact, it is no fern at all. It is a Selaginella, a spike moss in the lycopod group. It is also called African club moss or Krauss' spike moss, and its scientific species name is Selaginella kraussiana (family Selaginellaceae). Many club mosses belong to another lycopod family, the Lycopodiaceae.

Ferns below to a different branch on the green tree of life, they are not lycopods. The two evolutionary branches are about as different as a turtle and a salamander. We easily keep salamanders (and other amphibians) apart from turtles and tortoises in our brains, but green things from many different branches on the tree of life look very similar to us.

Lycopods evolved before ferns and have spores, just like ferns, but lycopods differ a lot in how their leaves are constructed. Look closely, and you can see that lycopods have branches and stems with tiny scale-like leaves. These leaves are called lycophylls.

Some people mix up this plant with mosses, but real mosses are smaller and do not have roots like lycopods do. Mosses also have scale-like leaves, called microphylls, and they are very similar to lycophylls just smaller. So club mosses and spike mosses are not mosses.

A branch of a Selaginella (Frosty Fern) showing many, many small scale-like leaves.
Photo (cc) BotanicalAccuracy.com

Ferns on the other hand have large leaves, often divided, and these leaves are called euphylls, which means 'true leaves'. Other groups with true leaves are conifers (needles!) and all flowering plants (oaks, grasses, and dandelions and such). True leaves have many veins in them (look closely), but lycophylls and microphylls have only one vein in each leaf.

So, the common name of this plant is often 'frosty fern', and it is not uncommon for common names to give the wrong impression of a plant's taxonomic belonging. Just think of names such as 'lucky bamboo' (not a bamboo at all) and reindeer moss (a lichen). Common names are everyday names, often traditional, used among people so we can communicate about the plants around us. The real problem starts when we think this plant is a fern. And that happens, and then the botanical mistake is a fact induced by the not-so-great common name. Such as in this example:

"Never allow the soil to dry around your frosty fern. This fern doesn't tolerate dry periods or waterlogged soil." (link to source at GardenGuides.com)

Suddenly the spike moss became a fern for real in that quote. And suddenly, a botanical inaccuracy have been introduced in our way of thinking about this plant, because of its name. So therefore it is best to avoid such common names and instead use names that are more appropriate, like Krauss' spike moss.

The same thing can happen among animals, but usually we know that guinea pigs are not pigs, and that seahorses are not horses, and that ant lions are only very, very distantly related to lions. All because animals are a little more charismatic than plants and it is easier for us to relate to them as pets, food, dangers, or just crazy, cool species. (In reality plants are more of your food than animals are and as dangerous and cool as animals.)

Here is a great blogpost about this plant and its botanical inaccuracies from New Hampshire Garden Solutions. George Rogers has also written about this plant in a great little article in North County Current. Just remember not to introduce this non-native plant to your subtropical garden in southern United States, since it can easily become invasive.

What is Botanical Accuracy?

Would you care if someone called a cat 'a mouse' in the description of a medieval painting?

Would you care if someone served you horse meat, but said it was beef? I bet you would.

Would you care if the wrong chemical was listed in the ingredient list of your shampoo or cereal?

Would you care if you bought one plant, but got another?

Would you care if there were species or ingredient mistakes in advertising, menus, herbal pills, and such things?

Would you care if books on plants are illustrated with the wrong plants?

If so, here is the place for you to read about such problems in the world of plants and plant products, where unfortunately such mistakes, inaccuracies, and problems are not uncommon. This is usually due to lack of botanical knowledge or expertise, or sometimes because of plain ignorance.

Inaccuracies are common when it comes to plants, because it seems like we humans care to learn less about green things like trees, flowers, and herbs than we care to learn about animals, even when we eat plants, paint them, plant them, extract their chemicals, or use them in numerous other ways.

Without plants in the world you and I certainly would be dead. Some plants can also kill you with their toxins, so it is best to know which plant is what species. Time to learn some botany!

About mistakes, inaccuracies, and errors

Science is a process of gaining knowledge and understanding of the world around us. It is a never-ending process, and what we think are true facts today might change tomorrow. In science we are aiming for having the best understanding possible today based on what we and our predecessors have learned until now.

This means that what is botanically accurate from a scientific viewpoint might (and will) change. Other experts in the field of botany know a lot more about their particular research plants than I do. New scientific findings and conclusions are being published every day. This is just normal and part of the scientific process; we improve on our knowledge all the time.

The important thing is our willingness to continuously aim for botanical accuracy and the highest scientific standards in our use of names and facts. When things are wrong, let's correct them. Let us not perpetuate wrong botanical knowledge by accepting its incorrect use on commercial products, in everyday language, or in other parts of our contemporary cultures. Through scientific education and specific corrections we will improve botany and science for everybody, in supermarkets, restaurants, and garden centers.

It is the perpetuation of incorrect facts that are the problem, not the need for correction. Everybody makes mistakes, and everybody learns, throughout their lives. We need words to be able to communicate and talk about things, so let's use the right words and the right species names.

Undoubtedly there will be mistakes and errors on this blog, or things that need to be updated. If you want to get in touch, please e-mail me at botanicalaccuracy at gmail.com. If you see a mistake on this blog, e-mail me with the link to the post and an explanation what is incorrect and should be updated. If you represent a company and want to get in touch, please use the same e-mail address.