14. Rumex triangulivalvis (Danser) Rech. f. (syn.: R. salicifolius Weinm. var. triangulivalvis (Danser) Hickman, R. salicifolius subsp. triangulivalvis Danser) (N-Am.) – A rare, usually ephemeral alien. Formerly recorded regularly as a wool alien in the Vesdre valley, at least between 1913 and 1939. Subsequently, fairly frequent on dumps in the 1950’s and 1960’s. Apparently decreasing in the past decades. Sometimes persistent for several years, for instance at Antwerpen-Linkeroever between 1935 and 1940. Most recently seen along river Maas in 1995 (and claimed as naturalised in nearby riparian habitats in the Netherlands; see van der Meijden 2005). There is a remarkable concentration of records of Rumex triangulivalvis in the surroundings of Mons in 2010, all by riverlet Haine (canal): single individuals have been recorded in Jemappes, Mons and Saint-Ghislain (Verloove 2013). Possibly overlooked.
Rumex triangulivalvis is here treated in a narrow sense, following Mosyakin (2005). In W-European literature it is usually referred to as Rumex salicifolius Weinm. but this species has a rather small native distribution range and does not occur as an alien outside this range.
 |
|
 |
 |
Selected literature:
Lang W. (1981) Der Weidenblatt-Ampfer (Rumex triangulivalvis), eine neue adventive Art der Pfälzer Flora. Mitt. Pollichia 69: 180-184.
Mosyakin S.L. (2005) Rumex. In: Flora of North America Editorial Committee (eds.), Flora of North America, vol. 5. Oxford University Press, New York-Oxford: 489-533.
Van der Meijden R. (2005) Heukels’ Flora van Nederland (23e druk). Wolters-Noordhoff, Groningen: 685 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]