Phoradendron

Phoradendron is a genus of mistletoe, a group of evergreen parasitic plants that attach to the branches of living trees. It comprises several species native to the Americas and the Caribbean. Members are hemi-parasites: they perform photosynthesis but rely on host trees to obtain water and minerals via specialized structures called haustoria.

Phoradendron species form dense, woody clumps on hosts, with small leaves and inconspicuous flowers. They produce fleshy drupes containing seeds that are dispersed by birds, notably thrushes and waxwings. The seeds adhere to a suitable host branch and germinate, the resulting haustorium penetrating the host’s cortex to access xylem and sometimes phloem.

They occur on a wide range of hardwood hosts, including oaks, maples, elms, sycamores, pecans, and cypress in various regions. Ecological effects include reduced vigor, branch dieback, and increased vulnerability to other stresses; heavy infestations can damage timber and ornamental trees.

Distribution: primarily in the Americas, from southern Canada through the United States to Central and South America, including the Caribbean. Notable species include Phoradendron leucarpum (American mistletoe), Phoradendron serotinum (Virginia mistletoe), and Phoradendron californicum (California mistletoe).

Management involves removing infested branches or whole plants, typically by pruning, along with monitoring and, in some regions, targeted chemical or biological controls. Phoradendron plays a role in native ecosystems as a food source for birds and as a canopy-dwelling parasite that contributes to tree community dynamics.