They are woody hemi-parasitic shrubs with branches 10–80 cm (3.9–31 in) long, which grow on other trees. The foliage is dichotomously branching, with opposite pairs of leaves; these are fairly large, 2–5 cm (0.79–2.0 in) long, green and photosynthetic in some species (e.g. P. leucarpum), but minimal in some others (e.g. P. californicum). Although they are able to photosynthesize the plant relies of its host for some nutrients. The plant draws its mineral and water needs, and some of its energy needs, from the host tree using a haustorium which grows into the stems of the host. Different species of Phoradendron tend to use different host species, though most species are able to utilise several different hosts.
The flowers are inconspicuous, greenish-yellow, 1–3 mm (0.039–0.12 in) diameter. The fruit is a berry, white, yellow, orange, or red when mature, containing several seeds embedded in very sticky juice; the seeds are dispersed when birds (notably Cedar Waxwings and Phainopeplas) eat the fruit, and remove the sticky seeds from the bill by wiping them on tree branches where they can germinate.
The foliage and berries of some species are toxic. Leafy mistletoe seldom kill but they cause stress during and reducing crop productions in fruits and nut trees.
Read more about Phoradendron: Host and Symptoms, Disease Cycle, Environment, Management, Wildlife & Human Uses, Importance, Selected Species, References