Mistletoe (Phoradendron species) is a parasitic plant that occurs nearly worldwide. Mistletoe can be leafless or occur with leaves depending on the species. It, like all mistletoe plants is considered parasitic because it robs water and nutrients from other plants instead of from the ground. Despite some species not having leaves, all species of mistletoe have chlorophyll and do photosynthesize like a regular plant.
Mistletoe produces fragrant flowers and red berries if it is a female plant. There are two genders instead of one in this plant. It appears as a cluster of greenish-gray material hanging in a tree. Mistletoe is very detrimental to its host and eventual death of the host tree is common after infestation of some more detrimental species.
Mistletoe seeds are covered with a mucus like glue substance that when cleaned from the bills, vomited up from the bird or pooped out still remains stuck and adheres the seed to whatever it touches. Ideally for the mistletoe seed that object would be a good host tree.
Mistletoe glue can be used for weak glue applications straight off of the plant. Simply gather some berries and crush and grind them into submission! After removing the seed and the covering you will be left with a substance that feels and looks a lot like snot. This glue is stronger and thicker than snot but isn't nearly as strong as other glues, at least not at this point.
It is called glue, but I don't know if it ever gets hard like glue. If it does it does not happen quickly.
One application of the glue was to coat a branch with the substance and when a bird landed on it, the bird would be trapped.
Some say it is possible to thicken and strengthen the glue by allowing the glue to ferment for two or three weeks, then re-mashed into a thick paste.
Others say that you collect the berries in summer when still green, cook on low heat for 8 hours. Remove the green parts. Store covered for 20 days. Re-mash and again store away for 5 days. Then boil for an unknown amount of time. Trial and error I guess.
I need to do some testing to find a refined technique.