Chenopodiastrum S. Fuentes, Uotila & Borsch
Literature: Fuentes-Bazan & al. (2012).
Chenopodiastrum is a recent segregate of Chenopodium and accommodates glabrous or glabrescent (not persistently farinose) species with 5 perianth segments, horizontal seeds and 5 stamens (Fuentes-Bazan & al. 2012). It comprises 5 species (with representatives in both the Old and New World), two of which are native (or at least archaeophytic) in Belgium: Chenopodiastrum hybridum (L.) S. Fuentes, Uotila & Borsch (syn.: Chenopodium hybridum L.) and C. murale (L.) S. Fuentes, Uotila & Borsch (syn.: Chenopodium murale L.). Both are also regularly introduced, the latter mainly with cereals but also as a container weed in plant nurseries. Chenopodiastrum hybridum now mostly occurs as an introduction (often from grain) and might be extinct as a genuinely native species.
1. Leaf blades (at least in part) distinctly cordate at base, with 3-5 acute lobes on either side === 2
1. Leaf blades cuneate at base. Seeds distinctly keeled at edges (native) === Chenopodiastrum murale
2. Seed coat very finely rugulose, nearly smooth and shiny, not adherent to the seed === Chenopodiastrum simplex
2. Seed coat deeply pitted, dull, adherent to the seed (native) === C. hybridum
References
Fuentes-Bazan S., Uotila P. & Borsch T. (2012) A novel phylogeny-based generic classification for Chenopodium sensu lato, and a tribal rearrangement of Chenopodioideae (Chenopodiaceae). Willdenowia 42(1): 5-24. [available online at: http://www.ingentaconnect.com/content/bgbm/will/2012/00000042/00000001/art00001] Uotila P. (2001) Chenopodiaceae. In: Jonsell B. (ed.), Flora Nordica, vol. 2. The Bergius Foundation, Stockholm: 1-57.