Amaranthus watsonii Standl., 2006

Raus, Thomas, 2022, Taxonomic, nomenclatural and floristic review of Amaranthaceae of Greece and neighbouring countries, Willdenowia 52 (3), pp. 335-357 : 348

25. Amaranthus watsonii Standl. in Bull. Torrey Bot. Club 41: 505. 1914. – Holotype: North America , Mexico, Sonora, on sand near Guaymas, Oct 1887, Palmer 312 ( US US 00106268; isotypes: US US 01013502, US US 01013512).

Remarks — This is a dioecious taxon native to sandy and weakly saline coastal and inland areas of SW North America, in the U.S.A. and NW Mexico ( Mosyakin & Robertson 2003: 418). In Europe it is reported as a rare casual in Britain ( Brenan 1961) and Greece ( Arianoutsou & al. 2010). It was found once in Peloponnisos S of Gytheio in 2003 (Raus 2006) but has not been recorded since; the species may have vanished in the country. It differs from Amaranthus palmeri chiefly on its broadly spathulate, obtuse, pubescent perianth segments of the female flowers ( Sauer 1955: 38).