Amaranthus dubius Mart. ex Thell.

Raab-Straube, Eckhard von & Raus, Thomas, 2025, Euro + Med-Checklist Notulae, 18, Willdenowia 55 (1), pp. 107-144 : 110

Amaranthus dubius Mart. ex Thell. – Fig. 2.

A Cr: Greece, Kriti (Crete): Nomos of Chania, Eparchia of Sfakia, lower entrance of Imbros gorge, 35°11'N, 24°10'E, 70 m, ruderal habitat by a chapel, plants erect, to 80 cm tall, 29 Oct 2023, Strid 61793 (B, as Amaranthus powellii S. Watson , det. Th. Raus). – First record from Greece of this casual amaranth with thin, sometimes flexuous, whitish green, leafless terminal pseudo-spikes, bracts shorter than perianth, and circumscissile fruits. It is native to Central America, the Caribbean and NW South America S to Bolivia, introduced into C and E Africa, SW Asia, China and part of the Pacific islands, and commonly used as vegetable crop in the tropics. In Europe, it has been reported in France ( Thellung 1912), Germany ( Aellen 1959), and recently Bulgaria ( Delipavlov & Cheshmedzhiev 2011) as an infrequent introduction from several sources, especially waste of imported cocoa, coffee, citrus fruits, wool, cotton, and birdseed. In the Cretan locality, A. dubius was the dominant plant in a small, fenced area of c. 5 × 5 m. The only other species collected with it was Euphorbia hypericifolia L. (Strid 61794, UPA), another alien that appears to be spreading in the S Aegean area (see Muer & al. 2024). Amaranthus dubius is very close to A. spinosus and differs from it, apart from the absence of spines, almost only by the distribution of the sexes in the inflorescence (not separated in a basal female and an apical male portion as in the latter) and by blunt (not acute or spinytipped) female perianth segments ( Thellung 1914).

Th. Raus & A. Strid