Amaranthus bouchonii Thell.

Raus, Thomas, 2022, Taxonomic, nomenclatural and floristic review of Amaranthaceae of Greece and neighbouring countries, Willdenowia 52 (3), pp. 335-357 : 339

5. Amaranthus bouchonii Thell. in Monde Pl. 27: 4. 1926 ≡ Amaranthus hybridus subsp. bouchonii (Thell.) O. Bolós & Vigo in Butl. Inst. Catalana Hist. Nat., Secc. Bot. 38: 89. 1974 ≡ Amaranthus powellii subsp. bouchonii (Thell.) Costea & Carretero in Sida 19: 964. 2001. – Lectotype (designated by Hügin 1987: 466, 473): Europe, France, Bordeaux, Allée du Boutaut, chemin remblaye avec des balayures du port, 25 Sep 1925, Bouchon (BAS; isolectotypes: US US 106237 [fragment; see Iamonico 2016a: 521], Z Z000000239 [fragment]).

Remarks — Hügin’s effective lectotypification of the name Amaranthus bouchonii ( Hügin 1987: 466, 473) makes Iamonico’s subsequent designation of the identical lectotype superfluous ( Iamonico 2016a: 520). The type was definitely accepted as such by the prior typifying author, and the type element was clearly indicated by direct citation including the term “Typus (lecto)”; the phrase “designated here” (hic designatus) or an equivalent is mandatory only on or after 1 Jan 2001 ( Shenzhen Code Art. 7.11.) but is literally published in Hügin (1987: 473, “als Lectotypus wird daher die Pflanze in Basel (BAS) gewählt [therefore the sheet kept in Basel (BAS) is chosen as the lectotype]”). Bouchon’s original specimen is kept in BAS (Herbarium generale adventivum); a barcode will be available after completion of the digitization of the collection (currently under preparation, see https://herbarium.unibas.ch/de /sammlungen/digitalisierung/). Fragments in US and Z are annotated as duplicates by the monographer Thellung; no type material is found in Bouchon’s personal herbarium at LA and P (see Hügin 1987).

Amaranthus bouchonii is considered of W European origin, presumably evolved in SW France by mutation in populations of the adventive alien A. powellii ( Wilkin 1992; Costea & al. 2001a; Iamonico 2015b). It is established as a ruderal, agricultural and horticultural weed in W and C Europe ( Hügin 1986, 1987; Iamonico 2015a). In Greece, it was first found in 1980 (Kriti, Geropotamos plain, Raus 1997; see Table 1), now met with elsewhere in Greece as an infrequent casual alien with naturalization status so far unknown ( Arianoutsou & al. 2010), additionally published from the Aegean islands of Lesvos ( Bazos & al. 2007: 206) and Thasos ( Biel & Tan 2016: 432) and from Nomos Florina in NW Greece ( Willing & Willing 2018: 57) but probably more widespread in the country. Specific rank is advisable because constancy of critical morphological and carpological characters in A. bouchonii was experimentally proven on plants cultivated for eight years in contact with A. hybridus , A. powellii and A. retroflexus ( Costea & al. 2001a); in addition, Hügin (1986; 1987: 473) found specific discontinuities in germination of A. bouchonii , A. powellii and A. retroflexus . Subspecific rank under A. hybridus or A. powellii , as advocated by various authors, seems inappropriate because A. bouchonii is not known to occur in the North American native ranges of A. hybridus or A. powellii with a diverging distribution pattern; Mosyakin & Robertson (2003) signified the formal recognition of A. bouchonii in North American material as “premature”.