Pioneer Valley Fern Society

Fern Allies - Clubmosses 5

Blue Ground Cedar or Deep Root Creeping Cedar

Blue Ground Cedar (Diphasiastrum tristachyum) has a number of common names, but that is the most common and descriptive. It is related to Clubmoss #3 in this series, Southern Ground Cedar. It grows in dry sandy, open, sunny places and disturbed sites such as power line right-of-ways. The latter is where we find it around here. It grows throughout MA and the Northeast, out to the Midwest and down to GA. It often forms dense clusters or mats.

The most distinctive features are its blue-green color, and the horizontal levels of growth. There are 2 to 3 levels of sterile branches rising on the stem, with the higher level of branches squared off in profile across the top. The candelabra of 3-4 strobili (fertile cones) on each once or twice forked stem rises high above the branches. It is easier to see than to describe! Note the blue-green color and the flat-topped levels of sterile branches in the photo, taken along the power line at Mt. Toby.

Another important feature is a deeply buried horizontal stem, which is one key way to identify the Blue Ground Cedar from the Southern Ground Cedar or Fan Clubmoss, if the blue-green color is not enough.