Amaranthus retroflexus

Raus, Thomas, 2022, Taxonomic, nomenclatural and floristic review of Amaranthaceae of Greece and neighbouring countries, Willdenowia 52 (3), pp. 335-357 : 347

19. Amaranthus retroflexus L., Sp. Pl.: 991. 1753. –

Lectotype (designated by Townsend 1974: 12): Herb.

Linn. No. 1117.22 (LINN).

= Amaranthus delilei J. A. Richt. & Loret in Bull. Soc. Bot. France 13: 316. 1866 ≡ Amaranthus retroflexus var. delilei (J. A. Richt. & Loret) Thell. in Vierteljahrsschr. Naturf. Ges. Zürich 52: 442. 1907 ≡ Amaranthus retroflexus subsp. delilei (J. A. Richt. & Loret) Tzvelev in Novost Sist. Vyssh. Rast. 32: 183. 2000. – Type: not designated.

Remarks — Amaranthus retroflexus is native to North America, from SE Canada to NE Mexico. It is introduced as an agricultural and ruderal weed in warm-temperate regions worldwide ( Bayón 2015: 294) and in Europe was already common around 1800 AD ( Thellung 1914: 257). Naturalized in Greece ( Arianoutsou & al. 2010), it is the most widespread amaranth countrywide, formerly locally cultivated as vegetable crop (βλίτα, see Heldreich 1862). The name A. delilei applies to plants with short, weak (less rigid) floral bracts scarcely exceeding the perianth ( Loret 1866); they are hardly distinct from A. retroflexus ( Thellung 1912) . Putative hybrids with A. cruentus , A. hybridus and A. powellii have been reported from Greece ( Krigas & Kokkini 2004).