8. Rumex patientia L. (SE-Eur., SW-As.) – A rather frequent and probably recently increasing garden escape. Usually seen in road verges, on canal banks or dumps. Perhaps more widespread in Flanders than in Wallonia.
Rumex patientia is a rather variable species but Belgian populations are fairly homogenous. They are characterised by reddish stems and valves ca. 5-6 mm wide with only one well-developed tubercle and belong to subsp. patientia. In the British Isles subsp. orientalis (Bernh.) Danser with whitish-green stems, wider valves often with three (one large and two smaller) tubercles is by far the commonest taxon and the usual garden plant (Lousley & Kent 1981). It should be looked for in Belgium as well (see also Raycheva 2009).
Rumex patientia belongs to a group of closely related species (Rechinger 1933). Several are much alike and might have been neglected in Belgium. All share the rather tall habit of Rumex patientia. Rumex cristatus has valves with short, irregular teeth and nerves of leaves making an angle of 60-90° with the midrib (vs. more often ca. 45-60° but sometimes up to 90° in R. patientia as well) (see for instance Hetzel & Meierott 2002). Rumex longifolius DC. – formerly probably cultivated in Belgium and sometimes seen as an escape before 1870 – has all valves without tubercles, leaves with undulate margins and is slightly smaller. It occurs in most neighbouring countries (native as well as introduced) and is not rare. Recently seen, for instance, along river Maas in the Netherlands (van der Meijden 2005). Finally, Rumex xerubescens (see above) is often very reminiscent of either R. cristatus or R. patientia.
 |
 |
|
|
Selected literature:
Hetzel G. & Meierott L. (2002) Rumex cristatus DC. in Würzburg – ein bemerkenswerter Neufund für Deutschland. Flor. Rundbr. 36(1-2): 1-9.
Hoste I. (2006) Rumex patientia. In: Van Landuyt W., Hoste I., Vanhecke L., Van den Bremt P., Vercruysse W. & De Beer D., Atlas van de flora van Vlaanderen en het Brussels gewest. Instituut voor Natuur- en Bosonderzoek, Nationale Plantentuin van België en Flo.Wer: 775-776.
Lousley J.E. & Kent D.H. (1981) Docks and knotweeds of the British Isles (BSBI Handbook n° 3). BSBI, London: 205 p.
Raycheva T. (2009) Critical reassessment of the distribution of some taxa of Rumex subgenus Rumex (Polygonaceae) in Bulgaria – 2. Phytol. Balcan. 15(2): 155-169.
Rechinger K.H. (1933) Vorarbeiten zu einer Monographie der Gattung Rumex, 2. Die Arten der Subsektion Patientiae. Feddes Repert. 31: 225-283.
Van der Meijden R. (2005) Heukels’ Flora van Nederland (23e druk). Wolters-Noordhoff, Groningen: 685 p.
Verloove F. (2002) Ingeburgerde plantensoorten in Vlaanderen. Mededeling van het Instituut voor Natuurbehoud n° 20: 227 p.