Araliaceae
Molecular phylogenetic research supports the inclusion of the genus Hydrocotyle (sometimes set aside in a distinct family, the Hydrocotylaceae) in the Araliaceae (Chandler & Plunkett 2004). It was traditionally placed in Apiaceae (see also Lambinon & al. 2004). Stace (2010) adopts an alternative taxonomy and accepts Araliaceae and Hydrocotylaceae as distinct families.
In addition to the genera included in this account, several others are grown as ornamentals (e.g. Lawrence 1959). They produce berries that are eaten and dispersed by birds. One of these species, Kalopanax septemlobus (Thunb.) Koidz., was reported as self-sowing in a garden where it was planted in Oudenaarde in 2018.
1. Low herbaceous plants, rooting at the nodes. Leaves peltate or petiolate from a deep basal sinus. Inflorescence inconspicuous, always shorter than the subtending leaf === Hydrocotyle
1. Woody plants, climbers, shrubs or small trees. Leaves never peltate or petiolate from a deep basal sinus (at most cordate at base). Inflorescence often very conspicuous and much longer than the subtending leaf (except sometimes in Hedera) === 2
2. Plant climbing or sprawling, with numerous adventitious roots. Evergreen. Inflorescence a simple umbel === Hedera
2. Plant erect, without adventitious roots. Deciduous or evergreen. Inflorescence compound === 3
3. Deciduous. Plants with or without spines. Leaves to 3-pinnately compound, leaflets papery to membranous, not leathery === Aralia
3. Evergreen. Plants without spines. Leaves palmately lobed, not pinnately compound, leathery === Fatsia
Literature
Chandler G.T. & Plunkett G.M. (2004) Evolution in Apiales: nuclear and chloroplast markers together in (almost) perfect harmony. Bot. J. Linn. Soc. 144: 123-147.
Frodin D.G. & Govaerts R. (2003) World checklist and bibliography of Araliaceae. Royal Botanic Gardens, Kew: 444 p.
Hussner A. (2007) Zur Biologie des aquatischen Neophyten Hydrocotyle ranunculoides L. f. (Apiaceae) in Nordrhein-Westfalen. Flor. Rundbr. 40: 19-24.
Jonsell B. & Karlsson T. (eds.) (2010) Flora Nordica, vol. 6. The Bergius Foundation, Stockholm: XIII + 298 p.
Jury S.L. (2004) The Euro+Med treatment of Hedera (Araliaceae) – recent studies and a new name. Willdenowia 34: 351-352.
Lambinon J., Delvosalle L., Duvigneaud J. (avec coll. Geerinck D., Lebeau J., Schumacker R. & Vannerom H. (2004) Nouvelle Flore de la Belgique, du Grand-Duché de Luxembourg, du Nord de la France et des Régions voisines (Ptéridophytes et Spermatophytes). Cinquième édition. Jardin botanique national de Belgique, Meise: CXXX + 1167 p.
Lawrence G.H.M. (1959) The cultivated genera of Araliaceae. Baileya 7: 133-140.
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.