Amaranthus hybridus

Raus, Thomas, 2022, Taxonomic, nomenclatural and floristic review of Amaranthaceae of Greece and neighbouring countries, Willdenowia 52 (3), pp. 335-357 : 344-345

publication ID	https://doi.org/10.3372/wi.52.52304
persistent identifier	https://treatment.plazi.org/id/F26687CE-2178-FFA7-FCF9-F94064E77961
treatment provided by	Felipe
scientific name	Amaranthus hybridus
status

Treatment

13. Amaranthus hybridus View in CoL L., Sp. Pl.: 990. 1753. – Lectotype (designated by Townsend 1974: 19): Herb. Linn.

No. 1117.19 (LINN).

= Amaranthus chlorostachys Willd., Hist. Amaranth. View in CoL : 34. 1790. – Lectotype (designated by Iamonico 2016a: 521): origin unstated, Hermes (B B - W 17521 -01 0).

= Amaranthus patulus Bertol., Comment. Itin. Neapol. View in CoL : 19. 1837 ≡ Amaranthus retroflexus subsp. patulus (Bertol.) Bonnier & Layens, Tabl. Syn. Pl. Vasc. View in CoL France: 265. 1894 ≡ Amaranthus hybridus subsp. patulus (Bertol.) Carretero View in CoL in Collect. Bot. 11: 127.

–

– 1979. – Lectotype (designated by Iamonico 2016a: 525): Europe, Italy, Campania, Napoli al Pasconcello , Sep 1834, Bertoloni (BOLO) .

“ Amaranthus cruentus ” sensu Greuter & al. (1984: 46) View in CoL , pro parte [non Amaranthus cruentus View in CoL L., Syst. Nat., ed. 10: 1269. 1759].

“ Amaranthus hypochondriacus ” sensu Greuter & al. (1984: 47) View in CoL , pro parte [non Amaranthus hypochondriacus View in CoL L., Sp. Pl.: 991. 1753].

Remarks — Amaranthus hybridus is native to temperate North America and C and N South America and is introduced as a segetal and ruderal weed in warm-temperate regions worldwide ( Bayón 2015: 285). It is recorded in all parts of Greece, where it is considered naturalized ( Arianoutsou & al. 2010). The distribution map in Strid & Tan (1997: map 259) is rather outdated by recent fieldwork (see, e.g., Willing & Willing 2006: 38). In Mediterranean basic floristic literature, the name A. hybridus has repeatedly been misapplied to A. powellii , the related weedy amaranth with longer floral bracts (2.3–3.7 times as long as perianth vs 1.3–1.5(–2.0) times longer in A. hybridus ) and stiffly erect, compact inflorescence branches (vs slender, ± patent ones in A. hybridus ). It is also similar to A. quitensis but all perianth segments are acute (never spathulate and apically obtuse as in A. quitensis ) and the inflorescence is green (not pale brownish green and without protuberant, membranous perianths in the male flowers as in A. quitensis ). Literature records of A. cruentus and A. hypochondriacus based on the taxonomy adopted by Greuter & al. (1984: 46, 47) may largely refer to A. hybridus and need to be verified by revised herbarium specimens. Rejection of the name A. hybridus L. as ambiguous (in favour of A. patulus Bertol. ; see Hügin 1987) is not advisable because it is clearly typified ( Brenan 1961; Sauer 1967; Townsend 1974) and has been used in the correct sense in recent basic floras.