Shrubs have berries for a reason. They are an vital part of the plant's reproductive method. Berries are eaten by birds or animals, who are only interested in the juicy fleshy part of the berry. After eating the berry, the animals wander off to other areas, and eventually deposit the seed part of the berry, which has not been digested in the stomach, so passed through the body in the normal way.
In some instances, the digestive juices of the stomach do a little bit of work on the hard seed shell - making it more ready to germinate in the position where it is deposited - ready to form a new plant.
The berries of Mistletoe on the other hand, are spread by birds onto neighbouring trees where they are unwittingly (habitually?) forced into the crevices of bark as they try to separate the sticky outer flesh of the mistletoe berry from the inner hard seed.
It seems in this instance, that the actual seed within the berry, is best separated from the desirable flesh, rather than gulping down the while lot and allowing the digestive system to take its natural course, with the conclusion being the depositing of the seed in distant places.
The mistletoe is rarely deposited on the same tree - for this would give the parent plant more competition for the sap of the tree on which the parasitic plant lives.
Berries and berrying shrubs are often scoffed at by gardeners, as well as being scoffed by birds! As can be seen in the images, berrying shrubs can add a range of colours to the winter garden, often from mid august through until February or March. It is interesting to note that many shrubs with berries, have a prolonged flowering period - as well as berries.
Pyracantha Berry Christmas - Pink - turning red - berries from August right through until Christmas - if you can keep the birds from them! All of the Pyracanthas have the added benefits of being evergreen and flowering for a few weeks in June.
Pyracantha Orange Glow - Golden Yellow Berries from August until December
Pyracantha Orange Charmer & Golden Charmer. Two great varieties of wall or fence shrubs with berries
Pyracantha Orange Charmer & Golden Charmer
Callicarpa bodineri 'Profusion'. Unusual colour berries on this deciduous shrub. Berries start in August/September and are held on the shrub until December. The foliage has an attractive autumn tint, but the flowers earlier in the year are of no ornamental consequence.
Rosa rugosa. The hips or berries on this rose are a great source of food for the birds.
Malus Golden Hornet
Sorbus aucuparia Huphensis - Pink Berries on this Mountain Ash medium sized tree. The berries persist into December.
Cotoneaster rothschildianus. Lightest yellow berries on this group of mainly evergreen shrubs
By David Hughes - firstname.lastname@example.org