Apiales

The Apiales are an order of flowering plants, included in the asterid group of dicotyledons. Well-known members of Apiales include carrots, celery, coriander, parsley, parsnips, poison hemlock, ginseng, ivies, and pittosporums.

Apiales consist of nine families, with the type family being the celery, carrot or parsley family, Apiaceae.

Taxonomy

There are nine accepted families within the Apiales, though there is some slight variation and in particular, the Torriceliaceae may also be divided.<ref name="plunkett2004">Template:Cite journal</ref>

• Apiaceae (carrot family)
• Araliaceae (ginseng family)
• Griseliniaceae
• Myodocarpaceae
• Pennantiaceae
• Pittosporaceae
• Torricelliaceae

The present understanding of the Apiales is fairly recent and is based upon comparison of DNA sequences by phylogenetic methods.<ref name="gregory2004">Template:Cite journal</ref> The circumscriptions of some of the families have changed. In 2009, one of the subfamilies of Araliaceae was shown to be polyphyletic.<ref name="nicolas2009">Template:Cite journal</ref>

The order Apiales is placed within the asterid group of eudicots as circumscribed by the APG III system.<ref name=APGIII2009/> Within the asterids, Apiales belongs to an unranked group called the campanulids,<ref name="winkworth2008">Template:Cite journal</ref> and within the campanulids, it belongs to a clade known in phylogenetic nomenclature as Apiidae.<ref name="cantino2007">Template:Cite journal</ref> In 2010, a subclade of Apiidae named Dipsapiidae was defined to consist of the three orders: Apiales, Paracryphiales, and Dipsacales.<ref name="tank2010">Template:Cite journal</ref>

Under the Cronquist system, only the Apiaceae and Araliaceae were included here, and the restricted order was placed among the rosids rather than the asterids. The Pittosporaceae were placed within the Rosales, and many of the other forms within the family Cornaceae. Pennantia was in the family Icacinaceae. In the classification system of Dahlgren the families Apiaceae and Araliaceae were placed in the order Ariales, in the superorder Araliiflorae (also called Aralianae).

Gynoecia

The largest and obviously closely related families of Apiales are Araliaceae, Myodocarpaceae and Apiaceae, which resemble each other in the structure of their gynoecia. In this respect however, the Pittosporaceae is notably distinct from them.<ref name="osk">Template:Cite journal</ref>

Typical syncarpous gynoecia exhibit four vertical zones, determined by the extent of fusion of the carpels. In most plants, the synascidiate (i.e. "united bottle-shaped") and symplicate zones are fertile and bear the ovules.<ref name="pan">Template:Cite book</ref> Each of the first three families possess mainly bi- or multilocular ovaries in a gynoecium with a long synascidiate, but very short symplicate zone, where the ovules are inserted at their transition, the so-called cross-zone (or "Querzone").<ref name="osk"/>

In gynoecia of the Pittosporaceae, the symplicate is much longer than the synascidiate zone, and the ovules are arranged along the first. Members of the latter family consequently have unilocular ovaries with a single cavity between adjacent carpels.<ref name="osk"/>