Apiaceae

Most Apiaceae are annual, biennial or perennial herbs (frequently with the leaves aggregated toward the base), though a minority are woody shrubs or small trees such as Bupleurum fruticosum. Their leaves are of variable size, and alternately arranged, or with the upper leaves becoming nearly opposite. The leaves may be petiolate or sessile. There are no stipules but the petioles are frequently sheathing, and the leaves may be perfoliate. The leaf blade is usually dissected, ternate, or pinnatifid, but simple, and entire in some genera, e.g. Bupleurum. There is often variation in the functionality of the stamens even within a single inflorescence. Some flowers are functionally staminate (where a pistil may be present but has no ovules capable of being fertilized) while others are functionally pistillate (where stamens are present but their anthers do not produce viable pollen). Pollination of one flower by the pollen of a different flower of the same plant (geitonogamy) is common. The gynoecium consists of two carpels fused into a single, bicarpellate pistil with an inferior ovary. and often contain essential oils, containing aromatic compounds that are responsible for the flavour of commercially important umbelliferous seed such as anise, cumin and coriander. The shape and details of the ornamentation of the ripe fruits are important for identification to species level. == Taxonomy ==

Apiaceae was first described by John Lindley in 1836. The name is derived from the type genus Apium, which was originally used by Pliny the Elder circa 50 AD for a celery-like plant. The alternative name for the family, Umbelliferae, derives from the inflorescence being generally in the form of a compound umbel. The family was one of the first to be recognized as a distinct group in Jacques Daleschamps' 1586 Historia generalis plantarum. With Robert Morison's 1672 Plantarum umbelliferarum distribution nova it became the first group of plants for which a systematic study was published. The family is solidly placed within the Apiales order in the APG III system. It is closely related to Araliaceae and the boundaries between these families remain unclear. Traditionally groups within the family have been delimited largely based on fruit morphology, and the results from this have not been congruent with the more recent molecular phylogenetic analyses. The subfamilial and tribal classification for the family is currently in a state of flux, with many of the groups being found to be grossly paraphyletic or polyphyletic. Genera The number of genera accepted by sources varies. , Plants of the World Online (PoWO) accepted 444 genera, while GRIN Taxonomy accepted 462. The PoWO genera are not a subset of those in GRIN; for example, Haloselinum is accepted by PoWO but not by GRIN, while Halosciastrum is accepted by GRIN but not by PoWO, which treats it as a synonym of Angelica. The Angiosperm Phylogeny Website had an "approximate list" of 446 genera. File:Angelica archangelica (1118596627).jpg|Angelica archangelica File:Coriandrum sativum 003.JPG|Umbel of Coriandrum sativum showing strong zygomorphy (asymmetry) in the outer flowers. File:Members of the apiaceae family.2.png|4 Apiaceae family members: Daucus carota, Heracleum mantegazzianum, Pastinaca sativa, Laser trilobum == Ecology ==

The black swallowtail butterfly, Papilio polyxenes, uses the family Apiaceae for food and host plants for oviposition. The 22-spot ladybird is also commonly found eating mildew on these plants. == Uses ==

Many members of this family are cultivated for various purposes. Parsnip (Pastinaca sativa), carrot (Daucus carota) and Hamburg parsley (Petroselinum crispum) produce tap roots that are large enough to be useful as food. Many species produce essential oils in their leaves or fruits and as a result are flavourful aromatic herbs. Examples are parsley (Petroselinum crispum), coriander (Coriandrum sativum), culantro, and dill (Anethum graveolens). The seeds may be used in cuisine, as with coriander (Coriandrum sativum), fennel (Foeniculum vulgare), cumin (Cuminum cyminum), and caraway (Carum carvi). Other notable cultivated Apiaceae include chervil (Anthriscus cerefolium), angelica (Angelica spp.), celery (Apium graveolens), arracacha (Arracacia xanthorrhiza), sea holly (Eryngium spp.), asafoetida (Ferula asafoetida), galbanum (Ferula gummosa), cicely (Myrrhis odorata), anise (Pimpinella anisum), lovage (Levisticum officinale), and hacquetia (Sanicula epipactis). They then prey upon insect pests on nearby plants. Some of the members of this family considered "herbs" produce scents that are believed to mask the odours of nearby plants, thus making them harder for insect pests to find. Other uses The poisonous members of the Apiaceae have been used for a variety of purposes globally. The poisonous Oenanthe crocata has been used as an aid in suicides, and arrow poisons have been made from various other family species. Daucus carota has been used as coloring for butter. Dorema ammoniacum, Ferula galbaniflua, and Ferula moschata (sumbul) are sources of incense. The woody Azorella compacta Phil. has been used in South America for fuel. == Toxicity ==

Many species in the family Apiaceae produce phototoxic substances (called furanocoumarins) that sensitize human skin to sunlight. Contact with plant parts that contain furanocoumarins, followed by exposure to sunlight, may cause phytophotodermatitis, a serious skin inflammation. Phototoxic species include Ammi majus, Notobubon galbanum, the parsnip (Pastinaca sativa) and numerous species of the genus Heracleum, especially the giant hogweed (Heracleum mantegazzianum). Of all the plant species that have been reported to induce phytophotodermatitis, approximately half belong to the family Apiaceae. The family Apiaceae also includes a smaller number of poisonous species, including poison hemlock, water hemlock, spotted cowbane, fool's parsley, and various species of water dropwort. Some members of the family Apiaceae, including carrot, celery, fennel, parsley and parsnip, contain polyynes, an unusual class of organic compounds that exhibit cytotoxic effects. == References ==