Tamarix parviflora DC. (SE-Eur.) – A very rare but locally well-established escape from or (predominantly) relic of cultivation. Frequently planted in gardens and public places (for instance in the central reservation of motorways) but hardly (if at all) escaping. Tamarix parviflora is by far best represented in coastal dunes where it was formerly planted as a windbreak (chiefly along roadverges). At several places, essentially in the eastern portion of the Belgian coastal dunes, Tamarix parviflora now exists in dune grasslands, probably from transported rhizomes. Its presence was recently confirmed from the surroundings of Wenduine, Zeebrugge and Heist.
The exact identity of the Belgian populations of Tamarix parviflora long remained uncertain. They were previously ascribed to Tamarix tetrandra Pallas ex Bieb. Both are indeed very similar, much confused and sometimes – erroneously – considered to be conspecific. American records of Tamarix tetrandra also turned out to belong to T. parviflora (Baum 1967a) and it is the latter species that is extensively cultivated according to Baum (1978). The Belgian populations are distinguished as follows: bark brownish-red (not blackish), sepals1,1-1,6 mm long, slightly erose and conspicuously fused at base, bracts reddish-translucent almost to base and racemes ca. 5-6 mm wide at anthesis. These features are characteristic for Tamarix parviflora. However, petals are often slightly larger than in typical plants of the latter (2,2-2,5 mm in stead of 2 mm). Large-flowered plants have been observed in Turkey as well (Baum 1967b) and they possibly represent a mere cultivar of Tamarix parviflora. Recent molecular phylogenetic studies (Villar & al. 2019) confirmed specific status of these two species.
Literature
Baum B.R. (1967a) Introduced and naturalised tamarisks in the United States and Canada. Baileya 15: 19-25.
Baum B.R. (1967b) Tamarix. In: Davis P.H. (ed.), Flora of Turkey, vol. 2. Edinburgh University Press, Edinburgh: 349-351.
Baum B.R. (1978) The genus Tamarix. Israel Academy of Sciences and Humanities, Jerusalem: IX + 209 p.
Verloove F. (2006) Tamarix gallica. 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: 867.
Villar J.L., Angeles Alonso M., Juan A., Gaskin J.F. & Crespo M.B. (2019) Out of the Middle East: New phylogenetic insights in the genus Tamarix (Tamaricaceae). Journal of Systematics and Evolution. doi: 10.1111/jse.12478.