Blitum capitatum

Blitum capitatum L. (syn.: Chenopodium capitatum (L.) Ambr., C. blitum F. Muell.) (N-Am.) – A rare and much decreasing, always ephemeral alien. Formerly cultivated as a vegetable (or more rarely as an ornamental) and sometimes seen as an escape. Already known in the first half of the 19^th century and found in several different, widely scattered locations (Brussel, Leuven, Liège, Tournai, Verviers, etc.), most of the time as a weed in fields or gardens. In the 20^th century seen on various occasions (Hoboken, Lambermont, Vilvoorde, etc.) but obviously decreasing. Most recently seen in 1980 in the Botanic Garden in Meise (as a weed) and as a pavement in Wingene in 2019. Nowadays much less cultivated than in the past and rather unlikely to re-occur as an alien.

Blitum capitatum has been surprisingly often confused with native Oxybasis rubra (Chenopodium rubrum) in Belgian herbaria. In the vegetative state both are indeed very similar: non-mealy, more or less succulent, coarsely toothed leaves,… However, in Blitum capitatum leaves are usually more or less hastate at base (rather cuneate in O. rubra).