Dendrolycopodium

1. Leaves on the main axis (below the primary branches) spreading, at least on the upper portion of the axis.

D. dendroideum

1. Leaves on the main axis all appressed to strongly ascending.

2. Ultimate lateral branches flattened; the leaves unequal in size, the wide-spreading lateral leaves clearly longer than the ± appressed row of leaves on the underside of the branch.

D. obscurum

2. Ultimate lateral branches round; the leaves all equal in size and all ± equally ascending in orientation.

D. hickeyi

All species found in Dendrolycopodium

Dendrolycopodium dendroideumTREE CLUBMOSS 
Dendrolycopodium hickeyiPENNSYLVANIA CLUBMOSS 
Dendrolycopodium obscurumGROUND-PINE 

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. October 19, 2017. http://michiganflora.net/genus.aspx?id=Dendrolycopodium.