Interactions & Nutrition

Definition: Parasitism- Depending on a host for fitness, whereas the host can live without the relationship. It only suffers if the parasite is present.

As you may have guessed, being a parasite means that you MUST interact with another organism, or a parasitic relationship would not exist. So knowing this, we also know that Mistletoe is a plant where interactions are key to its survival. Phoradendron leucarpum grows on a huge variety of different trees, but it has been widely known to grow well on many oak species.

Different Interactions:

1) The first of many interactions which most Mistletoe goes through is the attachment of sticky seed to an unsuspecting bird or animal. The bird (or animal) then transports this seed to another tree, where it sticks to a branch.

2) Mistletoe uses haustorium as its primary means of connecting to the host plants and the water and nutrients within their xylem and phloem. These root-like structures usually develop early in the plants life, growing into the bark and diverting the transport systems of the host-plant to

themselves. To see more information about the Nutrition of Phoradendron leucarpum, click here! Sometimes, this diversion results in the death of the branch, but this only happens when almost all major xylem and phloem vessels are cut off. Often, these haustoria develop large galls, or lumpy deformations which are visible on the tree branch.

Hemi-Parasitic- Being parasitic, but also carrying out photosynthesis and creating its own sugars; like every other green plant.

Obligate Parasite- Needing the parasitic host for survival, for instance; if the host tree dies, so does the Mistletoe which grows on it.

Interactions with People:

Warning! American Mistletoe is poisonous to humans! Although many people love to hang mistletoe around Christmas time, this plant can cause you to become very ill if ingested.

To view how Mistletoe reproduces, click here!