Axyris, commonly known as Russian pigweeds, is a genus of annual herbaceous flowering plants in the amaranth family Amaranthaceae, placed within the order Caryophyllales. The genus is native to temperate regions of Eastern Europe and Asia, with the center of genetic diversity concentrated in the Altai mountain system and the northern Tien-Shan range of Central Asia.
Plants in this genus are typically small, erect or prostrate annuals with simple alternate leaves and inconspicuous wind-pollinated flowers, characteristic of the chenopod tribe within Amaranthaceae. The genus comprises around seven accepted species, including Axyris amaranthoides, A. hybrida, A. prostrata, A. sphaerosperma, A. mira, A. koreana, and A. caucasica.
The most widely known member is Axyris amaranthoides (Russian pigweed), which has spread far beyond its native Eurasian range to become a naturalized and at times invasive weed across northern North America, colonizing disturbed habitats such as roadsides, grain fields, and railway corridors.
Etymology
The common name "Russian pigweeds" reflects both the Eurasian origin of most species and their weedy habit, placing them alongside other amaranth-family plants colloquially called pigweeds.
Distribution
The genus is native to temperate Eastern Europe and Asia, with the highest diversity centered in the Altai and northern Tien-Shan mountains. Axyris amaranthoides has become widely naturalized as an invasive weed across northern North America.
Taxonomy Notes
Axyris is placed in the family Amaranthaceae (order Caryophyllales), the expanded amaranth family that now includes the former Chenopodiaceae. GBIF treats the genus as accepted with around seven recognized species.
