What is Mistletoe?

Mistletoes are semi-parasitic plants that grow on trees, bushes, and other plants. They draw water and mineral salts from their hosts, but they also carry out photosynthesis and produce carbohydrates that are full of energy.

There are several hundred mistletoe species which grow mainly in tropical and subtropical regions. They have various forms, leaves, blossoms, and fruits. There are evergreen mistletoes and others which shed their leaves at certain times. Some of them never grow leaves. Some have very beautiful colored flowers while others have flowers so tiny that they are barely visible. Their berries also vary considerably in size, color, and form. There are white, bright red, orange, and yellow berries.

Most mistletoe fruits contain a single seed, ensheathed by a sticky, slimy flesh. This flesh helps the seeds to stick to branches where they germinate and grow. Some mistletoes form small, explosive berries which hurl their seeds into the environment, but most fruits are eaten by certain birds which then drop the seeds in various places.

European Mistletoe

Viscum album is the only mistletoe species that grows wild in central Europe. This evergreen plant with its white berries is used as a decoration and a gift at Christmastime. It is also the only mistletoe species that grows as far north as Oslo, Stockholm, and equivalent latitudes. Extracts from this mistletoe are used in the treatment of cancer. It is useful to study the life of the mistletoe and to find out something about its properties. This can sometimes help to make improvements in the production of mistletoe preparations and in cancer therapy.

If we take a walk on a clear, mild, winter day, we may discover green, spherical bushes on the bare branches of trees. In springtime these spherical green shapes gradually disappear in the growing green masses of tree leaves. During summertime it is difficult to see mistletoe, even if one knows exactly where they are located. They reappear in late fall, when our trees become yellow, red, brown, and then shed their leaves. When the first white berries appear, one knows that Christmas is near. It is almost as if the mistletoes were concealed in the treetops during the summer, and come out of hiding in the winter, showing us its green leaves and stems, white, ripe berries, and small yellowish flowers. Mistletoe is a wonderful and joyous sight for many people, but a nuisance for others because this semi-parasite damages trees.

Thus, our decorative parasite and tree spoiler arouses contradictory feelings in people. Mistletoe brings hope and happiness, but it also stirs up anxiety and worries. There is something strange about mistletoe that fascinates some people, yet it makes others feel uncomfortable.

Reproduction and Germination

Mistletoe’s ripe berries are eaten in winter by mistle thrushes and other birds. The thrushes swallow the berries whole. The undigested slimy seeds are excreted and if they fall on a branch they stick to it. Back caps (Sylvia atricapillae) eat the flesh of the berries in the spring and they wipe the seeds, which stick to their much smaller beaks, onto the nearest branch. These two types of birds spread mistletoe by distributing its seeds onto branches, whereas titmice eat some of the seeds and prevent the mistletoe from spreading too abundantly. When a mistletoe seed is glued to a branch, it germinates in the light and warmth around the end of March in our latitudes. The seedling bends over and forms an adherent disc on the bark of the host branch, and it then tries to penetrate the bark. If it is able to reach the wood and