Water, Lamb's Quarters, Amaranth, Sow thistles, Common Chickenweed
red orach atriplex hortensis a beautiful plant
Atriplex (/ˈætrᵻplɛks/) is a plant genus of 250–300 species, known by the common names of saltbush and orache (or orach). It belongs to the subfamilyChenopodioideae of the familyAmaranthaceae (which include the Chenopodiaceae of the Cronquist system). 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. 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.
The species 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 alternate or rarely opposite leaves are petiolate or sessile, often persistent or tardily deciduous. The flat or slightly fleshy leaf blades are either entire, or serrate, or lobed and very variable in shape.
The inflorescences consist of axillary or terminal spikes or spicate panicles, or axillary clusters of glomeruled flowers. The flowers are unisexual, some species are monoecious, others dioecious. Male flowers consist of 3-5 perianth lobes and 3-5 stamens. Female flowers are usually lacking a perianth, but are enclosed by 2 foliaceous bracteoles, and contain an ovary with a short style and 2 stigmas.
In fruit, the bracteoles can enlarge, thicken or become appendaged. They enclose the fruit tightly, without becoming connate to it. The pericarp is adnate to the vertically orientated, flattened seed. The seed coat is thick, leathery or hardening. The annular embryo surrounds the perisperm.
The chromosome base number is x = 9, except for Atriplex lanfrancoi, which is x=10.
A few Atriplex species are C3-plants, but most species are C4-plants, with a characteristic leaf anatomy (kranz anatomy).
Distribution and evolution
The genus Atriplex is distributed nearly worldwide from subtropical to temperate and to subarctic regions. Most species-rich are Australia, North America, South America and Eurasia. Many species are halophytes and are adapted to dry environments with salty soils.
The genus evolved in Middle Miocene, the C4-photosynthesis pathway developed about 14.1-10.9 million years ago, when the climate became increasingly dry. The genus diversified rapidly and spread over the continents. The C4Atriplex colonized North America probably from Eurasia during the Middle/Late Miocene, about 9.8-8.8 million years ago, and later spread to South America. Australia was colonized twice by two C4 lineages, one from Eurasia or America about 9.8-7.8 million years ago, and one from Central Asia about 6.3-4.8 million years ago. The last lineage diversified rapidly, and became the ancestor of most Australian Atriplex species.
Ecology
Atriplex species are used as food plants by the larvae of some Lepidoptera species; see the list of Lepidoptera which feed on Atriplex. For spiders such as Phidippus californicus and other arthropods, saltbush plants offer opportunities to hide and hunt in habitat that is otherwise often quite barren.
Use by humans
The favored species for human consumption is now usually Garden Orache (A. hortensis), but many species are edible and the use of Atriplex as food is known since at least the late Epipaleolithic (Mesolithic).
Common Orache (A. patula) is attested as an archaeophyte in northern Europe, and the Ertebølle culture is presumed to have used it as a food. Its seed has been found among apparent evidence of cereal preparation and cooking at Late Iron Age villages in Britain. In the biblical Book of Job, mallûaḥ (מַלּ֣וּחַ, probably Mediterranean Saltbush, A. halimus, the major culinary saltbush in the region) is mentioned as food eaten by social outcasts (Job 30:4). Grey Saltbush (A. cinerea) is used as bushfood in Australia since prehistoric times. Chamiso (A. canescens) and Shadscale (A. confertifolia) were eaten by Native Americans, and Spearscale (A. hastata) was a food in rural Eurasia.
Meat from sheep which have grazed on saltbush has surprisingly high levels of vitamin E, is leaner and more hydrated than regular lamb and has consumer appeal equal to grain-fed lamb. The vitamin E levels could have animal health benefits while extending the shelf-life and maintaining the fresh red colour of saltbush lamb. This effect has been demonstrated for Old Man Saltbush (A. nummularia) and River Saltbush (A. amnicola). For reasons unknown, sheep seem to prefer the more fibrous, less nutritious River Saltbush.
Saltbushes are also used as an ornamental plant in landscaping and can be used to prevent soil erosion in coastal areas. Old Man Saltbush has also been successfully used to rehabilitate old mining sites around Lightning Ridge (Australia).
Systematics
The genus Atriplex was first described in 1753 by Carl Linnaeus. The type species (lectotype) is Atriplex hortensis.
Atriplex is an extremely species rich genus and comprises about 250-300 species. After phylogenetical research, Kadereit et al. (2010) excluded Halimione as a distinct sister genus. The remaining Atripex species were grouped into several clades, that mostly are not identical with the traditional sections:
Atriplex lanfrancoi/cana-Clade:
Atriplex lanfrancoi (Brullo & Pavone) G. Kadereit et Sukhor. (Syn.: Cremnophyton lanfrancoi Brullo & Pavone): endemic in Malta and Gozo.
Atriplex cana C.A. Mey.: from Eastern European Russia to Western China
Atriplex section Atriplex: annual C3-plants.
Atriplex aucheri Moq.: in Eastern Europe and West Asia
Atriplex hortensis L. – Garden Orache, Red Orach, Mountain Spinach, French Spinach: in Asia, cultivated or naturalized in Europe
Atriplex oblongifolia Waldst. & Kit. – Oblong-leaved Orache: in Eurasia
Atriplex sagittata Borkh. (Syn.: Atriplex nitens Schkuhr): in Eurasia
Atriplex davisii Aellen: from Southern Europe to Egypt
Atriplex glabriuscula Edmondston – Northeastern Saltbush, Babington's Orache, Smooth Orache, Scotland Orache, Glabrous Orache: In Central and Northern Europe
Atriplex gmelinii C.A. Mey. ex Bong. – Gmelin's Saltbush: in Asia and North America
Atriplex intracontinentalis Sukhor.: from Central Europe to Asia
Atriplex laevis C.A. Mey.: in Asia, naturalized in Eastern Europe
Atriplex latifolia Wahlenb.: in Eurasia
Atriplex littoralis L. – Grass-leaved Orache: in Eurasia and North Africa
Atriplex longipes Drejer – Long-stalked Orache: in Northern Europe
Atriplex micrantha C.A. Mey.: in Asia, naturalized in Europe
Atriplex nudicaulis Boguslaw – Baltic Saltbush: in Eurasia
Atriplex patula L. – Common Orache, Spreading Orache: in Eurasia and North Africa
Atriplex praecox Hülph. – Early Orache>: in Northern Europe
Atriplex prostrata Moq. – Spear-leaved Orache, Thin-leaved Orache, Triangle Orache, fat hen: in Eurasia and North Africa
C4-Atriplex-Clade: containing the majority of species. The traditional classification into sections (sect. Obione, sect. Pterochiton, sect. Psammophila, sect. Sclerocalymma, sect.Stylosa) did not reflect the phylogenetical relationships and was rejected by Kadereit et al. (2010).
Atriplex acanthocarpa (Torr.) S. Watson: in North America
Atriplex acutibractea Anderson: in Australia
Atriplex altaica Sukhor.: in Asia
Atriplex angulata Benth.: in Australia
Atriplex billardierei (Moq.) Hook. f.: in Australia
Atriplex canescens (Pursh) Nutt. – Chamiso, Chamiza, Four-winged Saltbush, Grey Sagebrush: in North America
Atriplex centralasiatica Iljin: in Asia
Atriplex cinerea Poir. – Grey Saltbush, Truganini: in Australia
Atriplex codonocarpa P.G. Wilson: in Australia
Atriplex conduplicata F. Muell.: in Australia
Atriplex confertifolia (Torr. & Frém.) S. Watson – Shadscale (Saltbush): in North America
Atriplex cordobensis Gand. & Stuck.: in South America
Atriplex deserticola Phil.: in South America
Atriplex dimorphostegia Kar. & Kir.: in North Africa
Atriplex eardleyae Aellen: in Australia
Atriplex elachophylla F. Muell.: in Australia
Atriplex fissivalvis F. Muell.: in Australia
Atriplex flabellum Bunge ex Boiss.: in Eurasia
Atriplex gardneri (Moq.) D. Dietr. – Gardner's saltbush, Moundscale: in North America
Atriplex glauca L.: in Portugal, Spain and in North Africa
Atriplex halimus L. – Mediterranean Saltbush, Sea Orache, Shrubby Orache: in South Europe, North Africa and Southwest Asia
Atriplex herzogii Standl.: in North America
Atriplex holocarpa F. Muell.: in Australia
Atriplex hymenelytra (Torr.) S. Watson – Desert Holly: in North America
Atriplex hymenotheca Moq.: in Australia
Atriplex imbricata (Moq.) D. Dietr.: in South America
Atriplex inamoena Aellen: in Eurasia
Atriplex intermedia Anderson: in Australia
Atriplex isatidea Moq.: in Australia
Atriplex laciniata L. – Frosted Orache: In Western and Northern Europe
Atriplex lampa (Moq.) Gillies ex Small: in South America
Atriplex lehmanniana Bunge: in Eurasia
Atriplex lentiformis (Torr.) S. Watson – Quail Bush: in North America
Atriplex leptocarpa F. Muell.: in Australia
Atriplex leucoclada Boiss.: in Eurasia
Atriplex leucophylla (Moq.) D. Dietr.: in North America
Atriplex lindleyi Moq.: in Australia
Atriplex moneta Bunge ex Boiss.: in Eurasia
Atriplex muelleri Benth.: in Australia
Atriplex nessorhina S.W.L. Jacobs: in Australia
Atriplex nummularia Lindl. – Old Man Saltbush, Giant Saltbush: in Australia
Atriplex obovata Moq.: in North America
Atriplex pamirica Iljin: in Eurasia
Atriplex parishii S. Watson: in North America
Atriplex parryi S. Watson: in North America
Atriplex parvifolia Kunth: in South America
Atriplex patagonica (Moq.) D. Dietr.: in South America
Atriplex phyllostegia (Torr. ex S. Watson) S. Watson: in North America
Atriplex polycarpa (Torr.) S. Watson – Allscale (Saltbush), Desert Saltbush, Cattle Saltbush, Cattle Spinach: in North America
Atriplex powellii S. Watson – Powell's Saltbush: in North America
Atriplex pseudocampanulata Aellen: in Australia
Atriplex quinii F. Muell.: in Australia
Atriplex recurva d'Urv.: in Eurasia, endemic to areas around the Aegean
Atriplex rhagodioides F. Muell.: in Australia
Atriplex rosea L. – Tumbling Orache: in Eurasia and North Africa
Atriplex rusbyi Britton ex Rusby: in South America
Atriplex schugnanica Iljin: in Asia
Atriplex semibaccata R. Br. – Australian Saltbush, Berry Saltbush, Creeping Saltbush: in Australia
Atriplex semilunaris Aellen: in Australia
Atriplex serenana A. Nelson ex Abrams: in North America
Atriplex sibirica L.; in Asia, naturalized in Europe
Atriplex sphaeromorpha Iljin: in Russia, Ukraine and Caucasus
Atriplex spinibractea Anderson: in Australia
Atriplex spongiosa F. Muell.: in Australia
Atriplex stipitata Benth.: in Australia
Atriplex sturtii S.W.L. Jacobs: in Australia
Atriplex suberecta I. Verd. – sprawling saltbush, lagoon saltbush: in Australia
Atriplex tatarica Aellen: in Europe, North Africa and Asia
Atriplex turbinata (Anderson) Aellen: in Australia
Atriplex undulata (Moq.) D. Dietr.: in South America
Atriplex velutinella F. Muell.: in Australia
Atriplex vesicaria Heward ex Benth. – Bladder Saltbush: in Australia
Selected species not yet investigated phylogenetically: