Lycopodium

 

Dendrolycopodium obscurum (Common Tree Club Moss).
A Lycopodium growing in
Rowan County, North Carolina. 

Lycopodium, or club moss, is not a moss at all but a seedless vascular plant. It belongs to an ancient lineage with its origin in the Devonian Period, over 400 million years ago.  Lycopodium was an early land plant and predated the dinosaurs.  Today’s club mosses are small plants but during the Carboniferous Period some Lycopodium relatives were giant trees. Coal deposits in the Appalachian Mountains contain the remains of Lycopodium that reached heights of over 100 feet.  

Lycopodium reproduces by spores made in sporangia that are shaped like clubs (thus the name club moss) and extend above the branched stems.  These stems bear tiny leaves that carry out photosynthesis.  

The genus Lycopodium formerly had 10 species in the Carolinas.  New research has broken that genus up into 7 genera and about 13 species.  I will use the name Lycopodium to refer to this group but use the currently accepted scientific name for each species in the blog. 

 

Dendrolycopodium obscurum with sporangia.
Rowan County, North Carolina. 

Dendrolycopodium obscurum, Common Tree Club Moss, is a small plant of the forest understory.  It has horizontally spreading branches that resemble tiny trees.  The upright plants we see are produced from an underground stem, a rhizome. Common Tree Club Moss is often seen in large stands or in a line all coming from a rhizome.   

 

A line of Dendrolycopodium obscuru from an underground rhizome. 
Rowan County, North Carolina. 

Lycopodiella alopecuroides, Foxtail Club Moss, grows along the ground with branching stems. This species grows in the wet, sandy soil of pine savannas on the Coastal Plain of the Carolinas. 

 

Lycopodiella alopecuroides, Foxtail Club Moss.
Wake County, North Carolina.  

Foxtail Club Moss with branching stems.
Wake County, North Carolina. 

Lycopodium reproduces by spores. These spores have interesting characteristics and some bizarre uses.  The spores are tiny, about 35 micrometers in diameter, and easily float on the air.  Plants release spores that are carried on the breeze, settle to the ground and establish new plants.   But if large numbers of Lycopodium spores are lofted into the air, they are highly flammable and even explosive.  The spores have a high wax content and a huge surface area.  This allows them to rapidly burn.  Lycopodium spores were used in the earliest flash photography.  Nineteenth century photographers would hold up a T-shaped tray filled with spores, squeeze a bulb to shoot the spores into the air and ignite them, giving a brief but brilliant flash to illuminate their subject.  Lycopodium spores have been used to produce theatrical stage flames and explosions.  In fact, Lycopodium spores are commonly called Dragon Breath by magicians who use it in their acts.  They were also used in Native American religious ceremonies. 

Danish-American photographer Jacob Riis using flash powder.
http://hspvaragtime.weebly.com/home/jacob-riis 

Video of flaming Lycopodium spores.

Rowan County, North Carolina. 

Lycopodium is a fascinating member of our flora.  The ancestors of these humble little plants were massive trees and their remains make up much of the coal we continue to burn and warm the planet.  When you see Lycopodium, think that long ago, it fed dinosaurs. 

A large stand of Dendrolycopodium obscurum.
Rowan County, North Carolina.