Amaranthus graecizans L.

In North America the name Amaranthus graecizans has been constantly misapplied to the common North American taxa A. albus and A. blitoides. Consequently, A. graecizans has been excluded from lists of North American plants. Recently, herbarium specimens (casual aliens collected in 1879 on ballast in Camden, New Jersey) of A. graecizans subsp. sylvestris were discovered (M. Costea et al. 2001b). Probably, the species disappeared in North America long ago, but, considering the long history of misidentification and confusion, there is also some chance that it may occur locally as an introduced species.

Three subspecies are usually recognized within Amaranthus graecizans in the Old World: subsp. graecizans, subsp. sylvestris (Villars) Brenan, and subsp. thellungianus (Nevski) Gusev. Only subsp. sylvestris, characterized by rhombic-ovate to elliptic-ovate leaves (as compared to lanceolate to almost linear leaves in subsp. graecizans) and comparatively large seeds has so far been reported from North America.

Despite its superficial similarity to Amaranthus albus and A. blitoides, A. graecizans seems to be more closely related to other Old World taxa with trimerous flowers.

Plants annual, pubescent in distal parts or becoming glabrescent at maturity. Stems erect to ascending or decumbent, branched at or distal to base, 0.1-0.9 m. Leaves: petiole variable in length; blade lanceolate to nearly linear or rhombic-ovate to elliptic-ovate, (1.5-)2-4(-5) × 1-3 cm, base cuneate to broadly cuneate, margins entire, plane, rarely indistinctly undulate, apex subacute to obtuse or emarginate, mucronulate. Inflorescences axillary glomerules, green. Bracts lanceolate, subspinescent, 1.5-2 mm, shorter or slightly longer than tepals. Pistillate flowers: tepals 3, erect, elliptic to lanceolate-elliptic, equal or subequal, 1.5-2 mm, apex short-acuminate; style branches slightly spreading; stigmas (2-)3. Staminate flowers intermixed with pistillate; tepals 3, equal or subequal; stamens 3. Utricles subglobose to broadly elliptic, 2-2.5 mm, slightly rugose, dehiscence regularly circumscissile, rarely irregularly dehiscent. Seeds black, lenticular, 1-1.3(-1.6) mm diam., smooth or indistinctly punctate.

Annual herb, branched from the base and usually also above, erect, decumbent or prostrate, mostly up to c. 45 cm. (rarely to 70 cm.). Stem slender to stout, angular, glabrous or thinly to moderately furnished with short to long, often crisped multicellular hairs which increase upwards, especially in the inflorescence, leaves glabrous or sometimes sparingly furnished on the lower surface of the principal veins with very short, gland-like hairs, long-petiolate (petiole from 3-4.5 mm, sometimes longer than the lamina), lamina broadly ovate or rhomboid-ovate to narrowly linear-lanceolate or linear, 4-55 x 2-30 mm, acute to obtuse or slightly retuse at the mucronulate tip, cuneate to long-attenuate at the base. Flowers all in axillary cymose clusters, male and female intermixed, males commonest in the upper whorls. Bracts and bracteoles narrowly lanceolate-oblong, pale-membranous, acuminate and with a pale or reddish arista formed by the excurrent green midrib, bracteoles subequalling or usually shorter than the perianth. Perianth segments 3, all 1.5-2 mm; those of the male flowers lanceolate-oblong, acute or subacute, pale-membranous with a narrow green midrib excurrent in a short, pale arista; those of the female flowers lanceolate-oblong to linear-oblong, gradually to abruptly narrowed to a very short to rather long mucro, the midrib often bordered by a green vitta above and apparently thickened, the margins pale whitish to greenish. Stigmas 3, slender, usually pale, flexuose, c. 0.5 mm. Capsule subglobose to shortly ovoid, 2-2.25 mm, usually strongly wrinkled throughout with a very short, smooth neck, slightly exceeding the perianth, circumscissile or sometimes not, even on the same plant. Seeds shining, compressed, black, 1-1.25 mm, faintly reticulate.

introduced; N.J.; native to Eurasia (Mediterranean area, s Asia); n Africa; locally introduced in Australia.

Flowering summer-fall.

On ballast; 0m.