2. Rumex x confusus Simonk. (= R. crispus x patientia) – A very rare but possibly overlooked hybrid. Discovered in 2011 in a grassy border at the Kennedybos in Kortrijk; a single plant was found with both parents (Verloove 2013). Rumex xconfusus shares the tall habit and distinctly red stems with R. patientia and the small valves with three, more or less equally developed tubercles with R. crispus. Its leaves are slightly undulate at margins (a feature of R. crispus) but much wider than in the latter (an influence of R. patientia). The inflorescence is somewhat laxer than in Rumex patientia but otherwise looks fairly fertile: most valves are fully developed but, on closer examination, the nuts prove to be mostly shrivelled.
Rumex xconfusus seems to be a rather rare hybrid (although both parents are often found together). It has been recorded in the British Isles (Lousley & Kent 1981) and in Sweden (Karlsson 2000).
 |
 |
 |
Literature:
Karlsson T. (2000) Polygonaceae. In: Jonsell B. (ed.), Flora Nordica, vol. 1. The Bergius Foundation, Stockholm: 235-318.
Lousley J.E. & Kent D.H. (1981) Docks and knotweeds of the British Isles (BSBI Handbook n° 3). BSBI, London: 205 p.
Verloove F. (2013) Verder onderzoek binnen het genus Rumex (Polygonaceae) in België. Dumortiera 102: 3-9. [available online at: http://www.br.fgov.be/DUMORTIERA/DUM_102/Dum_102_3-9_Rumex_Verloove.pdf]