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You are viewing an archived site. The Chesapeake Bay Introduced Species Database project ended in 2020 and the database is no longer receiving updates. Learn more…
Image of Atriplex patula

Atriplex patula

Plants

Orach

Orach (also called saltbush) is a shoreline plant that lives in salty soils at the margins of salt marshes and beaches. It is widely distributed in the Northern Hemisphere and has been introduced to many areas of the world. This wide distribution has resulted in some disagreement about whether it is native or introduced in North America. We consider it introduced based on its occurrence on dry ballast (rocks, etc. used to weight old sailing vessels in the 1600-1800s) and because it is mostly found in disturbed habitats. Orach likely arrived in dry ballast from Europe sometime before 1848, probably much earlier (1600s) because it was well established by the late 1800s. The earliest records in the Chesapeake region were from in Hampton Beach VA in 1872 and Washington DC in 1877. Orach is rare in the Chesapeake and so no impacts have been reported.

Image Credit: Anna-Lena Anderberg, Swedish Museum of Natural History

Description Taxonomy Invasion History Ecology Impacts References

Description

Atriplex patula was recognized by Gray (1867) as A. p. patula, with other species A. littoralis and A. prostrata, as varieties of A. patula (A. p. littoralis and A. p. hastata, respectively). Most Chesapeake and East Coast reports of A. patula probably refer to A. prostrata, unless more specific taxonomic information is given.

Taxonomy

Kingdom Phylum Class Order Family Genus
Plantae Magnoliophyta Magnoliopsida Caryophyllales Chenopodiaceae Atriplex

Synonyms

Atriplex patula var. bracteata; Atriplex patula var. japonica; Atriplex patula var. littoralis; Atriplex patula spp. typica; Atriplex erecta; Atriplex angusitfolia

Invasion History

Chesapeake Bay Status

First Record Population Range Introduction Residency Source Region Native Region Vectors
1872 Unknown Unknown Introduced Boundary Resident Europe Eurasia Shipping(Dry Ballast), Agriculture(Agricultural Weed)

History of Spread

Atriplex patula (Orach) is now widely distributed in the Northern Hemisphere, and has been introduced to 'many areas of the world' (Bassett and Munro (1987). Authors are somewhat divided on the status of A. patula. in North America. Gray (1848), Robinson and Fernald (1908), Fernald (1950), and Clemants (1992) treated it as native. Taylor (1915), Hulten (1958), Taschereau (1971), Bassett and Munro (1987), and Gleason and Cronquist (1991) consider it introduced from Eurasia. This judgement seems to be based on its occurrence on dry ballast, and its predilection for disturbed habitats. Taschereau (1972) says 'The distribution and anthopophilic habitat preferences of Atriplex patula strongly suggest that this species is introduced rather than native in North America'. We are treating A. patula as an introduction to North America.

Atriplex patula has been present in North America since before 1848 (Gray 1848), and was probably introduced much earlier. A reference in an account by John Josselyn, of a visit to New England colonies in 1663, to 'arrach' could refer to A. patula (Crosby 1986). It was well established by the late 1800s (Bassett and Munoro 1987), but taxonomic difficulties obscure its history. Atriplex patula was recognized by Gray (1867) as A. p. patula, with other species A. littoralis and A. prostrata, as varieties of A. patula (A. p. littoralis and A. p. hastata, respectively). Most Chesapeake and East Coast reports of A. patula probably refer to A. prostrata, unless more specific taxonomic information is given.

Fernald (1950), Bassett and Munro (1987) Gleason and Cronquist (1991) note from the Maritimes to NC, and sporadically across the continent to the West Coast. In NY and New England, A. patula ranges from 'saline and brackish areas near the coast'(Clemants 1992) with scattered inland occurrences across to the Great Lakes basin and the Hudson and Lake Champlain valleys (Clemants 1992; Magee and Ahles 1999). In PA, it ranges from the Delaware River westward across the state (Rhoads and Klein 1993).

The earliest records we found for A. patula were herbarium specimens, collected in Hampton Beach VA in 1872, and 'in vicinus Washington DC' in 1877 (US National Herbarium Collection). We have only two published Chesapeake Bay reports, Fernald’s (1950) 'shores of Chesapeake Bay' (as A. p. bracteata), probably based on his VA collecting in the 1930s and 40s, and ore piles in Canton, MD, on Baltimore Harbor (as A. japonica) (Reed 1964).

History references- Gray 1848; Gray 1867; Robinson and Fernald 1908; Taylor 1915, Fernald 1950; Hulten 1958; Reed 1964; Taschereau 1972; Crosby 1986; Bassett and Munro 1987; Gleason and Cronquist 1991; Clemants 1992; Rhoads and Klein 1993; Magee and Ahles 1999

Invasion Comments

Invasion Status- Clemants(1992), Kartesz's Biota of North America Program database and the USDA Plants database treat A. patula as native. Taschereau (1972) says “The distribution and anthropophilic habitat preferences of Atriplex patula strongly suggest that this species is introduced rather than native in North America”. Bassett et al.(1983) and Bassett and Munro (1987) also support introduced status.

Ecology

Environmental Tolerances

For SurvivalFor Reproduction
Minimum Maximum Minimum Maximum
Temperature (ºC)
Salinity (‰) 20.0 0.0 0.0 20.0
Oxygen
pH
Salinity Range fresh-poly

Age and Growth

Male Female
Minimum Adult Size (mm)
Typical Adult Size (mm)
Maximum Adult Size (mm)
Maximum Longevity (yrs)
Typical Longevity (yrs

Reproduction

Start Peak End
Reproductive Season
Typical Number of Young
Per Reproductive Event
Sexuality Mode(s)
Mode(s) of Asexual
Reproduction
Fertilization Type(s)
More than One Reproduction
Event per Year
Reproductive Startegy
Egg/Seed Form

Impacts

Economic Impacts in Chesapeake Bay

Atriplex patula (Orach) has no significant impacts in the Chesapeake Bay region because of its scarcity.

Economic Impacts Outside of Chesapeake Bay

Atriplex patula (Orach) is an occasional garden and crop weed in the US and Canada (Bassett and Munro 1987).

References- Bassett and Munro 1987

Ecological Impacts on Chesapeake Native Species

Atriplex patula (Orach) is probably too rare and local to have had significant impacts on native biota in the intertidal zone of Chesapeake Bay.

Ecological Impacts on Other Chesapeake Non-Native Species

Atriplex patula (Orach) is probably too rare and local to have had significant impacts on introduced biota in the intertidal zone of Chesapeake Bay.

References

Bassett, I. J.; Crompton, C. W.; McNeill, J.; Taschereau, P. M. (1983) The genus Atriplex (Chenopodiaceae) in Canada, Canada Department of Agriculture Monographs 31: 1-72

Bassett, I. J.; Munro, D. B. (1987) The biology of Canadian weeds. 81. Atriplex patula L., A. prostrata Boucher ex DC, and A. rosea L., Canadian Journal of Plant Science 67: 1069-1082

Clemants, Steven E. (1992) Chenopodiaceae and Amaranthaceae of New York State, New York State Museum Bulletin 485: 1- 26

Crosby, Alfred W. (1986) Ecological Imperialism: The Biological Expansion of Europe, 900-1900., In: (Eds.) . , London. Pp. 145-336

Fernald, Merritt L. (1950) Gray's Manual of Botany, In: (Eds.) . , New York. Pp.

Gleason, Henry A.; Cronquist, Arthur (1991) Manual of vascular plants of northeastern United States and adjacent Canada, In: (Eds.) . , Bronx, New York. Pp.

Gray, Asa (1848) A manual of botany of the northern United States., In: (Eds.) . , Boston. Pp.

Gray, Asa (1867) A manual of botany of the northern United States., In: (Eds.) . , New York. Pp.

Hulten, E. (1958) The Amphi-Atlantic Plants and Their Phytogeographical Connections, , Stockholm. Pp.

Reed, Clyde F. (1964) A flora of the chrome and manganese ore piles at Canton, in the port of Baltimore, Maryland and at Newport News, Virginia, with descriptions of genera and species new to the flora of the eastern United States., Phytologia 10: 321-406

Rhoads, Ann Fowler; Klein, William McKinley, Jr. (1993) The Plants of Pennsylvania, , Philadelphia. Pp.

Robinson, Benjamin Lincoln; Fernald, Merrit L. (1908) Gray's New Manual of Botany., , New York. Pp.

Taschereau, P. M. (1972) Taxonomy and distribution of Atriplex species in Nova Scotia, Canadian Journal of Botany 50: 1571-1594

Ungar, Irwin A. (1996) Effect of salinity on seed germination, growth, and ion accumulation of Atriplex patula (Chenopodiaceae), American Journal of Botany 83: 604-607

Direct questions and comments to chesnemo@si.edu.

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