Both Apiaceae and Araliaceae have a fairly cosmopolitan distribution, though Apiaceae is slightly more concentrated in temperate regions and Araliaceae in tropical climates. Pittosporaceae, on the other hand, is mostly abundant in Australasia. In fact, only one of Pittosporaceae's nine genera, Pittosporeae, grows naturally outside of this region; in eastern and western Africa (Heywood, 1993).
All over the world the three families are extensively used by humans for a wide variety of purposes. The seeds or fruits of Apiaceae are common spices such as coriander (Coriandum sativum), cumin (Cuminum cyminum), caraway (Carum carvi) and anise (Pimpinella anisum). In other cases the flavorful leaves and stems of Chervil (Anthriscus cerefollium), Dill (Anethum graveolens), and Parsley (Petroselinum crispum) are used as seasonings. The roots, and sometimes also the stems, of Apiaceae are often bulky and nutritious and serve as staple food in western parts of the world. Examples of these staple foods are celery, parsley, pignut and carrots. In some Native American diets species of Lomatium are an important source of nutrition (Heywood, 1993).
Species from the order Apiales do not only serve as nutrition, they sometimes also contain very strong compounds and are therefore used as medicine or poison. Ginseng (Panax quinquefolia), a species that belongs to the family Araliaceae, is one of the species that has such medical uses. Its roots, which have a slightly sweet and licorice taste, contain compounds that have stimulant and aphrodisiac qualities (Heywood, 1993). These qualities have long been known in Asia, though the root extract has mainly been used for its soothing qualities, and are now spreading all over the world. Other mebers of Apialea are used to treat gastrointestinal diseases, cardiovascular ailments, spasms and a variety of other ailments. In other cases the compounds, especially in many species of Apiaceaes, are so strong as to be used as poison. Perhaps the most famous victim of these toxic compounds is Socrates, who was killed by the Apiaceae Hemlock (Conium maculatum). Many species of Apiales are also very decorative plants. This is especially true of species from the family Pittosporaceae that are used economically, particularly because of their attractive flowers and foliage. These ornamental plants need mild and sheltered conditions and are therefore common in warm and temperate regions such as in New Zealand, Australia and some of the Mediterranean countries (Heywood, 1993).
English Ivy (Hedera helix) from the family Araliaceae was one such plant that was primarily grown as ornamental. Because of its effective seed dispersal, though, it is now considered a weed in many temperate regions of the world. Studies indicate that the fleshy fruits of English Ivy, which are mainly dispersed by birds, contain toxic compounds that enhance the seed dispersal in the following way. The toxic compounds in the fruit prevent birds from foraging a large amount of fruits in a short time. With the help of these toxins the plant avoids loosing its seeds to one big flock that would devour much, or all, of the fruit and carry such a large amount of the reproductive capacity with it. This would limit the dispersal of the seeds to the narrow path of a single flock. Because of the presence of the toxins each bird will spend a relatively short time on each bush, eating a small number of fruits. Because fruit is left over for new flocks to forage upon, seeds are dispersed to many different places, following the diverse paths of different flocks. This enhances the plant's capability of survival and reproduction, since a variety of different patrons of the fruit, rather than a single flock, will allow the seeds to reach a greater area.
The flowers of most species of Apiales are usually small and grouped into clusters. This arrangement is an adaptation especially designed to enhance pollination. The many flowers in clusters not only visually attract more pollinators than if they were spread out over the whole plant, their close proximity also makes possible the pollination of many flowers in a single visit from a polinator. Because of this arrangement the plant can spend less energy producing a large number of flowers and still have many of its flowers pollinated. In fact, not only does the plant benefit from this arrangement, the pollinators also save a considerable amount of energy visiting fewer places to collect pollen or nectar. In the case of Apiaceae the many small clusters of flowers may be further grouped into a compound umbel, which additionally aids in making pollination effective. These umbels are usually placed on top of a somewhat fragile stalk and therefore pollination by birds or bats is uncommon. Small insects such as bees, mosquitoes or beetles, on the other hand, are well-suited pollinators for these small flowers that contain the right amount of nectar and pollen. The flattened top of the compound umbel also provides a good landing platform for butterflies and moths, other common pollinators of the Apiales. Apiales seldom exhibit any specialization for specific pollinators but rather rely on a wide variety of insects (Heywood, 1993).
