Euphorbiaceae
Literature: Baillon (1874), Radcliffe-Smith (2001).
Phyllanthoid Euphorbiaceae are currently excluded from Euphorbiaceae, following recent molecular phylogenetic research (APGIII 2009). They are accommodated in a family of their own (Phyllanthaceae). Phylogenetic research furthermore supports the inclusion of Chamaesyce Gray (and Poinsettia J. Graham) in a broadly circumscribed genus Euphorbia (Zimmermann & al. 2010).
An overview of current research on Euphorbiaceae is available here: http://www.euphorbiaceae.org.
1 Leaves alternate, palmately lobed. Milky latex absent === 2
Leaves opposite or alternate, entire or serrate but never lobed. Milky latex present or absent === 3
2 Milky latex absent. Glands subtending each inflorescence bract 2. Stamens very numerous, up to 1000 === Ricinus
Milky latex present. Glands subtending each inflorescence bract absent. Stamens 10 === Manihot
3 Capsule 2-loculate. Milky latex absent. Leaves opposite. Plant usually dioecious (native) === Mercurialis
Capsule 3-loculate. Milky latex present. Leaves alternate or opposite. Plant monoecious === Euphorbia (incl. Chamaesyce and Poinsettia)
Additional aliens: Three species of Acalypha L. have recently been recorded as greenhouse weeds and/or as ephemeral introductions associated with container plants (Verloove 2006, Hoste & al. 2009): A. australis L., A. indica L. and A. virginica L. Thus far, none of these species was seen “in the wild” in Belgium but their occurrence in a near future is not unlikely.
Literature:
APG III (2009) An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants. APG III. Bot. J. Linn. Soc. 161(2): 105-121.
Baillon H.E. (1874) Monographie des Euphorbiacées. V. Masson, Paris.
Hoste I., Verloove F., Nagels C., Andriessen L. & Lambinon J. (2009) De adventievenflora van in België ingevoerde mediterrane containerplanten. Dumortiera 97: 1-16. [available online at: http://www.br.fgov.be/DUMORTIERA/DUM_97/Dum%2097_1-16_Mediterrane%20cont...
Radcliffe-Smith A. (2001) Genera Euphorbiacearum. Royal Botanic Gardens, Kew: X + 455 p.
Verloove F. (2006) Catalogue of neophytes in Belgium (1800-2005). Scripta Botanica Belgica 39: 89 p.
Zimmermann N.F.A., Ritz C.M. & Hellwig F.H. (2010) Further support for the phylogenetic relationships within Euphorbia L. (Euphorbiaceae) from nrITS and trnL-trnF IGS sequence data. Plant Syst. Evol. 286: 39-58.