A frequent sight on hikes and walks if you know where to look for them, clubmosses are a charming plants with an enchanting history.
In general, clubmosses prefer to grow in forested areas, particularly where there are conifer trees growing. They often go unnoticed due to their small stature and are commonly mistaken for moss. Both plant groups have similar visual characteristics and tend to grow in similar habitats. However, clubmosses are more closely related to ferns than they are to moss. As with many plants, botanists are still debating the technical classification of clubmosses. The leading theory suggests that although mosses, clubmosses, and ferns all reproduce by spores and not seeds, clubmosses and ferns have an added feature of vascular tissue and are more closely related.
The plants that began to colonize land millions of years ago had a low growing, small stature and did not reach great heights. As plants evolved, they developed a type of plumbing system made from specialized tissues that allowed them to transport water and nutrients up and down the plant. These tissues are called xylem and phloem and are often simply called the plant’s vascular system. Without a vascular system, the plant is vertically challenged and prevented from reaching great heights. The plants we know as moss today are small and spreading because they do not have a vascular system. Clubmosses and ferns however, evolved to have a vascular system and can grow taller than the mosses. Clubmosses are considered fern allies when thinking about their evolutionary relationship and can often be found in fern field guides
The generalized term clubmoss is thought to be derived from their club-like reproductive structures that grow on the tips of branches in some species. Not all clubmosses have prominent reproductive structures, as some have spore bearing structures under the leaves. Taking a closer look at clubmoss with a magnifying glass or hand lens is always fascinating and highly recommended!
Clubmosses take on a variety of forms with the two most recognizable being those that have a spreading appearance and those that look like miniature conifer trees. One similarity between clubmosses and the conifers is that they do not lose their leaves in the fall and can photosynthesize year-round. It is always a delight to see vibrant green clubmoss poking out of the snow on a cold winter day or in the fall when other vegetation has died back for the winter. In certain species of clubmoss, you can see an interesting structural marker that is similar to the growth rings on a tree. Clubmosses have annual constrictions, areas where the leaves tend to grow more spread out earlier in the season and then begin to grow closer together as winter approaches.
In Vermont there are 26 different species of clubmoss, several of which are extremely rare. Clubmosses are found worldwide and are represented by one family, Lycopodiaceae. Looking more closely, the family name might seem familiar. As Mary Holland points out in her wonderful book Naturally Curious, Lycopodium powder is made from the dried spores of clubmoss. The spores contain large amounts of aluminum and are extremely flammable, causing a bright flash of light often used for stage lighting in Victorian theaters. Lycopodium powder is still used today in a variety of ways and is used traditionally by Indigenous Peoples to treat wounds.
Although the clubmosses we are familiar with tend to barely reach a foot tall, evidence suggests that between 290-350 million years ago during the Carboniferous Period, clubmosses were enormous and roughly the size of trees! The decomposition and petrification of these giant clubmosses as well as other large ancient plants formed the coal beds that we rely on so heavily today. Hence the name, Carboniferous Period! The next time you are exploring in the woods, be on the lookout for the tiny giants we know as clubmoss! You’ll be delighted and intrigued by their miniature world.