Parasitic plants are plants that have developed the ability to directly use the nutrients produced by other plants. They attach themselves to the branches, trunk or roots of a host. Some types have the ability to produce their own nutrients as well with photosynthesis. Florida is home to many different species that attack the local pine forests as well as some agricultural crops.
American mistletoe (scientific name Phoradendron leucarpum) is the common mistletoe found hanging in homes during Christmas time. It inhabits deciduous hardwood trees sucking sap from the living layer of wood under the tree's bark. Mistletoe leaves do contain chlorophyll and it is capable of producing its own nutrients but it also can use the sap from the host plant. The host plant is also its primary source of water.
Mistletoe berries contain a very sticky seed. When birds eat the berries they often need to use a branch to wipe the seeds off their beaks. The seeds remain stuck to the tree limb, germinate and then attach themselves to the host tree. Mistletoe forms dense clumps about 1 to 3 feet across that are most noticeable after the trees have lost their leaves in the fall.
The tree, or tall, dodder (scientific name Cuscuta exaltata) is a very rare species of dodder that attacks trees instead of low shrubs. It has only been seen in seven counties in Florida and in Texas. This dodder attacks southern live oak, elms and several other types of tree. It is slightly larger than regular dodders and is a reddish-gold color.
Dodders are stringy parasitic annuals without chlorophyll that grow from seeds. Once a vine touches a host plant, it attaches itself and taps into the living layer of plant that lies just under the bark. It then draws nutrients directly from its host and eventually loses contact with the ground.
Black-senna (scientific name Seymeria cassioides) is a small annual shrub that primarily attacks pines, although it has been found in association with other tree species. It is found in the pine forests of Florida, can grow up to 4 feet tall and has many branches. The plant contains chlorophyll and is capable of producing some of its own food, but it requires a host to survive. The roots grow alongside the roots of the host and attach, tapping the nutrients within. It produces small yellow flowers in August through October and sets seeds before it dies off and turns completely black.