4. Rumex x erubescens (= R. obtusifolius x R. patientia) – A very rare but possibly overlooked alien, sometimes occurring among its parents. Usually persisting for several years but not really naturalised. Recorded in road verges since 2004 near Ardooie and between Zonnebeke and Ieper (Verloove 2008). Since then also observed in a few other places (e.g. Gent, Waregem, etc.).
Rather variable. Plants can be either highly sterile or nearly fully fertile. In the latter case, Rumex xerubescens is much reminiscent of Rumex cristatus DC. (syn.: R. graecus Boiss. et Heldr.), a native of SE-Europe but increasingly becoming naturalised elsewhere in Europe. For their distinction, see Verloove (2008).
 |
 |
 |
|
 |
 |
Selected literature:
Verloove F. (2008) Twee miskende Rumex-taxa in België. Dumortiera 95: 4-8.