“Ground Cedar” Club Moss

2018 January 6

In November, after most of the flowering plants have died back due to frost (but before it really starts to snow), there are some other kinds of plants that become more visible. Like these low plants forming a sort of ground cover, that we found while walking around the Churning Rapids Ski Trail on November 5, 2016:


These look a lot like cedar leaves, but they aren’t. For one thing, cedar is a tree or bush, and these never get more than a few inches tall.


For another thing, these are not only not trees, they aren’t even flowering plants. They are one of the varieties of spore-forming plants called “club mosses”, after the clublike shape of their spore heads, shown here in closeup:


The spore heads stick up on thin stalks above the main mass of the plants:


These in particular appear to be Diphasiastrum digitatum, also known as “ground cedar” or “fan clubmoss”. They grow mostly in the undergrowth in the woods, and once they get established they pretty much take over the undergrowth, particularly under evergreen trees like pines.

Clubmosses aren’t really mosses, they are vascular plants that have internal tube structures for carrying water and nutrients throughout the plant (true mosses don’t have that, which is why they don’t get very tall). Back in the Good Old Days (about 300 to 400 million years ago, in the Devonian and Carboniferous periods), the biggest plants were the club mosses, some of which were treelike objects up to 100 feet tall. Club mosses are copious producers of spores, and at the time they produced such massive spore clouds that there are now seams of coal (called “sporinite”) that are almost entirely composed of fossilized clubmoss and fern spores. Even today, walking through a patch of the modern clubmosses during spore season will produce dense clouds of spores. In fact, the spores (referred to as “lycopodium powder”) are popular for demonstrating dust explosions and for fireball effects in magic shows. When dispersed in air at the right concentration, the spores burn extremely brightly and very fast, but burn out so quickly that they generally don’t harm surfaces and have a relatively small likelihood of setting fire to buildings. Lycopodium powder is made from several of the more common clubmoss species, and these ground cedar clubmosses are one of the popular ones to collect it from.

2 Responses
  1. January 10, 2018

    Marvellous. I love that mosses form the same architectures as their more evolved cousins.

    I looked up Churning Rapids on Google Maps and as I did so, I wondered what your blog would be like if you lived in Brazil. You’d probably have covered only about 10% of the available insects by now.


  2. Crprod permalink
    January 12, 2018

    When I was growing up in rural Virginia, this was known as “running cedar ” and used in Christmas decorations.

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