Anabasis is a genus of flowering plants in the subfamily Salsoloideae of the family Amaranthaceae, placed within the order Caryophyllales. The genus comprises approximately 8 accepted species of annual or perennial herbs and subshrubs adapted to arid and semi-arid environments across the Old World.
Plants in this genus are recognisable by their fleshy, articulated (jointed) stems, which are mostly hairless except for tufts at the nodes. The opposite leaves are often reduced to small scales, an adaptation to minimise water loss, though some species bear more normally developed leaves. Inflorescences take the form of elongated or condensed spikes; flowers are solitary or in groups of up to four in the axils of upper leaves or bracts, each flower subtended by two paired bracteoles. Each flower has five subequal membranous perianth segments, three to five stamens, and an ovary topped by two or three thick, short stigmas.
The most distinctive feature of the genus appears in fruit: two or three of the five perianth segments develop large, prominent membranous wings, an adaptation that aids wind dispersal. Rarely, the perianth remains unwinged. The fruit itself may be fleshy (baccate) or dry, either flattened and vertical or nearly spherical. The seed is lenticular and vertically oriented, containing a spirally coiled embryo with no endosperm.
Anabasis is distributed from Southwest Europe and North Africa, through the shores of the Red Sea as far as Ethiopia, eastward to Southwest and Central Asia. The centre of diversity lies in Asia. Species are characteristic inhabitants of steppes and semideserts, where they play ecological roles as pioneer and cover plants on saline and gypsiferous soils. The species Anabasis aphylla has attracted scientific interest for its alkaloid content, particularly anabasine, used historically as an insecticide.
Etymology
The name Anabasis is borrowed from the Ancient Greek ἀνάβασις (anábasis), meaning "a going up" or "ascent," most famously the title of Xenophon's account of a Greek military expedition into Asia. The application of this name to the plant genus likely alludes to the upright, jointed stems characteristic of its members.
Distribution
Anabasis ranges from Southwest Europe and North Africa — including the shores of the Red Sea south to Ethiopia — eastward through Southwest Asia to Central Asia. The centre of diversity lies in Asia. Member species are characteristic of steppes, semideserts, and saline or gypsiferous soils.
Ecology
Anabasis species are adapted to dry, open habitats including steppes and semideserts. Their fleshy, articulated stems and scale-like leaves reduce water loss. The winged fruits of most species facilitate wind dispersal across open landscapes. Several species tolerate saline and gypsiferous substrates where competition from other plants is low.
Taxonomy Notes
Anabasis is placed in the subfamily Salsoloideae of the family Amaranthaceae (order Caryophyllales). GBIF records 8 accepted species, including Anabasis articulata, Anabasis aphylla, Anabasis salsa, Anabasis setifera, Anabasis cretacea, Anabasis prostrata, and Anabasis oropediorum.
