Alternanthera
Alternanthera Forssk.
Alternanthera is a taxonomically difficult genus of ca. 80-100 species (although many more have been described). Most are native in the tropics and subtropics of America and some in Africa, Asia and Australia. Some species have become pantropical agricultural or environmental weeds. A few are cultivated as ornamentals, especially Alternanthera ficoidea (L.) Sm. and related taxa (Jäger & al. 2008).
Species of Alternanthera formerly were among the typical wool aliens in the valley of river Vesdre but all remained strictly ephemeral. Only one species was recently found as a grain alien in Belgium.
Additional aliens: Alternanthera angustifolia R. Brown (Aus., wool alien), A. caracasana Humb., Bonpl. et Kunth (S-Am., wool alien), A. denticulata R. Brown (Aus., wool alien), A. nodiflora R. Brown (old world trop., wool alien), A. paronychioides A. St. Hil. (S-Am., wool alien), A. pungens Humb., Bonpl. et Kunth (S-Am., wool alien) and A. sessilis (L.) DC. (trop., wool alien).
Literature:
Chaudhury G. & Bhattacharya U.C. (1994) The genus Alternanthera Forssk. (Amaranthaceae) in India. Bull. Bot. Surv. India 36(1-4): 267-277.
Iamonico D. & Sánchez-Del Pino I. (2016) Taxonomic revision of the genus Alternanthera (Amaranthaceae) in Italy. Plant Biosystems 150(2): 333-342. [available online at: https://apirs.plants.ifas.ufl.edu/site/assets/files/373271/373271.pdf]
Jäger E.J., Ebel F., Hanelt P. & Müller G. (eds.) (2008) Rothmaler Band 5. Exkursionsflora von Deutschland. Krautige Zier- und Nutzpflanzen. Springer Verlag, Berlin: 880 p.
Mears J.A. (1977) The nomenclature and type collections of the widespread taxa of Alternanthera (Amaranthaceae). Proc. Acad. Nat. Sci. Philadelphia 129: 1-21.
Sánchez-del Pino Y., Motley T.J. & Borsch T. (2012) Molecular phylogenetics of Alternanthera (Gomphrenoideae, Amaranthaceae): resolving a complex taxonomic history caused by different interpretations of morphological characters in a lineage with C4 and C3-C4 intermediate species. Bot. J. Linn. Soc. 169: 493-517.
Singh A.K., Devi Y., Srivastava M. & Singh S. (2008) The genus Alternanthera Forssk. (Amaranthaceae) in south-eastern Uttar Pradesh. J. Econ. Taxon. Bot. 32(2): 393-402.
Van der Meijden R. & Veldkamp J.F. (1970) Drie voor Nederland nieuwe Amaranthaceae uit de geslachten Gomphrena en Alternanthera. Gorteria 5: 54-60.
Van Ooststroom S.J. & Reichgelt Th.J. (1961) Het geslacht Alternanthera Forsk. in Nederland. Gorteria 1: 2-6.