Atraphaxis

Species of Atraphaxis are much branched woody plants, forming shrubs or shrubby tufts. The current year's branchlets are herbaceous and bear the leaves and flowers. The leaves are simple and alternate, with very short stalks (almost sessile). The ochreas are membranous and usually two-veined, more-or-less joined at the base. The inflorescence is made up of several bundles (fascicles) of one to three flowers. The flowers have persistent tepals, either arranged in a narrow tube with unequal lobes or bell-shaped with equal segments. The fruits are wingless achenes.^[2]

The genus Atraphaxis was erected by Carl Linnaeus in 1753. As with many other genera in the family Polygonaceae, the boundaries between the genera have been unclear, and some or all species placed in other genera. Molecular phylogenetic studies have shown that Atraphaxis forms a distinct clade.^[2][3] The genus is placed in the tribe Polygoneae of the subfamily Polygonoideae. Within the tribe, it is most closely related to the genera Duma and Polygonum, forming the so-called "DAP clade".^[3]

As of March 2019^[update], Plants of the World Online accepted 41 species:^[1]