Atriplex (/ˈætrɪplɛks/[2]) is a plant genus of about 250 species, known by the common names of saltbush and orache (/ˈɒrɪtʃ, -ətʃ/;[3][4] also spelled orach). It belongs to the subfamily Chenopodioideae of the family Amaranthaceae s.l.. The genus is quite variable and widely distributed. It includes many desert and seashore plants and halophytes, as well as plants of moist environments. The generic name originated in Latin and was applied by Pliny the Elder to the edible oraches.[5] The name saltbush derives from the fact that the plants retain salt in their leaves; they are able to grow in areas affected by soil salination.
Species of plants in genus Atriplex are annual or perennial herbs, subshrubs, or shrubs. The plants are often covered with bladderlike hairs, that later collapse and form a silvery, scurfy or mealy surface, rarely with elongate trichomes. The leaves are arranged alternately along the branches, rarely in opposite pairs, either sessile or on a petiole, and are sometimes deciduous. The leaf blade is variably shaped and may be entire, tooth or lobed.[6][7][8][9][10]
The flowers are borne in leaf axils or on the ends of branches, in spikes or spike-like panicles . The flowers are unisexual, some species monoecious, others dioecious. Male flowers have 3-5 perianth lobes and 3-5 stamens. Female flowers are usually lacking a perianth, but are enclosed by 2 leaf-like bracteoles, have a short style and 2 stigmas.[6][7][8][9][10]
After flowering, the bracteoles sometimes enlarge, thicken or become appendaged, enclosing the fruit but without adhering to it.[6][7][8][9][10]
A few Atriplex species are C3-plants, but most species are C4-plants, with a characteristic leaf anatomy, known as kranz anatomy.[11]
The genus Atriplex was first formally described in 1753 by Carl Linnaeus in Species Plantarum.[1][12][13] The genus name was used by Pliny for orach, or mountain spinach (A. hortensis).[14]