Ganoderma-zonatum or “Butt Rot” infects palm trees primarily within the first 4-5 feet of the trunk.  The fungus lives in the trunk and spreads to the tree through its root system.  Early symptoms include yellowing or wilting leaves of the palm, slower growth rate than normal and excessive die-off of fronds. Infestation of this fungus originates within the trunk with millions of spores and will first present soft, white, irregularly-shaped circles on the trunk of the tree, eventually forming into conks or basidiocarp,  which are a hard growth identified by a rust-colored top and white bottom.  The fungus then attacks the tissue of the palm, primarily the lignin and cellulose, and over time destroys the xylem which is the tissue responsible for water transport throughout the tree.  The trunk of the tree will remain hard after Ganoderma has rotted the butt unlike other types of rot which make the wood soft and weak.  This can be misleading during inspection because the tree appears solid and can be assumed to be structurally sound when in fact it is at great risk of falling. The only definitive way of diagnosing a living tree with Ganoderma is by identifying the conks attached to the trunk.  However, palms can be infected and die without any conks being present if the palm is experiencing the advanced stage of the fungal infection. If a tree is determined to be infected it should be removed immediately, including the stump.  After removal it is important to consider the soil at the site of the removal to be infected and it is recommended to use a species of tree other than palm varieties if re-planting is desired. While there are many types of fungi affecting trees in Florida, Ganoderma is a specific pathogen of palms and will not infect other species such as hardwoods and conifers.  It is important to hire a professional to perform a consultation on your trees if you suspect them of having Ganoderma-zonatum.