Crystallofolia

The other day a friend and I happened to be at the right place at the right time. We got to see something that is a cold weather phenomenon known by several names.

Crystallofolia on dittany (Cunila origanoides). All the following photos show this phenomenon on the same species of plant shown here.

Ice doodles, frost flowers and ice ribbons are all names that have been attributed to these beautiful and ephemeral frozen sculptures. Not all these terms are the most accurate as these have nothing to do with frost and they really aren't flower or ribbons, though the names are very descriptive. Professor Emeritus Robert T. Harms (1932-2016) from the University of Texas at Austin, proposed the name, crystallofolia. Taken from Latin and Greek roots, it simply means "ice leaf". He does not take credit for this as original thought though. He points out that the term "eisblatt", which means the same thing, was used in the past by German botanists.

Regardless of what name we affix to them they are beautiful, interesting and rare. Like salamanders to a vernal pool in the spring, conditions have to be just right in order for these icy creations to form. Dr. Harms lists only a few native North American plants have been documented as being able to produce the ice formations. They include, dittany (Cunila origanoides), frostweed (Helianthemum canadense), white crownbeard (Verbesina virginica) and marsh fleabane (Pluchea odorata). Why some plants support this phenomenon and others do not is not yet settled by scientists. However, the process by which the ice is formed is known as ice segregation. I won't try and distill that process here, as I will freely admit to not quite grasping the physics of it myself. However, Dr. James R. Carter, Professor Emeritus of Illinois State University, explains the process in an excellent article about ice flowers published in American Scientist. The article is titled, Flowers and Ribbons of Ice. Here is the link, but in the case that it becomes outdated, simply use your favorite search engine.

The science behind the these sculptures is fascinating and worth learning about. These are also rare enough that they provide ample motivation to explore the outdoors on cold mornings. In the meantime, enjoy a few more photos of these amazing crystallofloia.

Posted by: Robyn Wright-Strauss