Flat-Branched Tree Clubmoss

Lycopodium obscurum

While performing a wetland delineation yesterday at Annapolis Harbour Center, I came across a large aggregate of flat-branched tree clubmoss.  It was nice to see a native evergreen, knowing that we were going to get in excess of a foot of snow within the next 24-hours.  Seeing the attractive plants make me yearn for spring as the forest floor will light-up with spring ephemeral wildflowers, but we will have to wait two more months for that.
Having some free time, being snowed-in, I did some homework on clubmoss. The two common clubmosses in central Maryland are Lycopodium obscurum and Lycopodium digitatum (think digits or fingers for their club formation).Flat-branched tree clubmoss is native to the eastern United States. It grows in the understory of acidic pine and hardwood forests, growing in clonal colonies. The plant can grow by spore (seed) or by rhizome. The process of developing from a spore to a mature clubmoss with strobili (fertile spike, the club) takes approximately 20-years.The rhizome of the plant typically produces only one upright shoot per year. In the beginning of the spring growing season, the rhizome grows out to an inch and then forms one branch. The produced branch is weak but serves as a reserve rhizome apex, with the potential to become a new main rhizome. First-year shoots are unbranched and usually do not penetrate the soil surface. Second-year shoots however, undergo rapid growth, usually reaching near their final heights, and forming lateral branches. The stem that runs along the ground can reach a length of up to 4-feet when fully grown.
These small evergreen plants are well adapted for winter. Their leaves are covered with a waxy material, minimizing water loss. Clubmosses contain an antifreeze-like substance that prevents their cells from freezing and bursting.Clubmosses are protected from herbivores (deer) by chemicals called alkaloids (nicotine and caffeine are examples of alkaloids) that cause them to taste bad.The dried spores of clubmoss is a yellow powder (known as Lycopodium), which contains high amounts of aluminum and causes a bright, fast burning fire when ignited. They were used in the early days of photography as a source of flash. I have used a lighter to ignite the club head and have watched miniature explosions. How cool!