Description
Potentially Misidentified Species - Chenopoium rubrum (Red Goosefoot) is a northern native marsh sp., rare in MD; C. album is an introduced upland species. A variety of other rarer introduced Chenopodium spp. are known from disturbed upland areas, ore piles, and ballast (Brown and Brown 1984; Reed 1964). A. prostrata (Halberd-Leaved Orach) is a marsh species, possibly introduced.
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Plantae | Magnoliophyta | Magnoliopsida | Caryophyllales | Chenopodiaceae | Dysphania |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1739 | Established | Stable | Introduced | Boundary Resident | Europe | South America | Ornamental(Garden Escape) |
History of Spread
Dysphania ambrosioides (Mexican Tea, formerly Chenopodium ambrosioides) is native to tropical America, but it was probably widely dispersed by Native Americans as an important medical plant. By the 18th century, D. ambrosioides was cultivated in Europe for medicinal purposes, as a source of wormseed oil (a cure for intestinal worms, hence the synonym C. anthelminthicum, meaning 'anti-worm') (Fernald et al. 1958). It was an early and common garden escape, and was among MD herbarium specimens collected before 1753 (Brown et al. 1987), and also was collected by Clayton in VA in 1730's (Gronovius 1739; Reveal 1983). It was widespread in the eastern U.S. in the early 19th century: 'on road sides, Pennsylvania and Virginia; plentiful in the streets of Philadelphia' (Pursh 1814); 'roadsides; Connecticut and westward; rare except at the South' (Gray 1848; as Ambrina anthelminthica). Fernald (1950) gave a similar range and habitat description: 'waste places; cut ground etc.; common southwards; north to New England; NY; Southern Ontario; WI; LS.; etc.' (Fernald 1950). It is now reported from 45 contiguous U.S. states, from ME to FL and TX, and from CA to WA (Natural Resources Conservation Service 2001).
Dysphania ambrosioides is listed by Brereton (1831) for Washington, and Aikin (1837) for Baltimore and in subsequent Washington-Baltimore floras. It is found in nearly every VA county (Harvill et al. 1992), but is 'now rare' in MD. Dysphania ambrosioides was once grown commercially in Carroll County, MD for wormseed oil (Brown and Brown 1984). It is predominantly an upland plant, but was reported as uncommon on 'beach margins' on the Potomac River, King Georges County (Simmons et al. 1995), as 'occasional on the sand strand' in the Norfolk-Virginia Beach area (Kearney 1901), and in "upper salt marsh", on Wallops Island, VA (Klotz 1986). It occurs on the upper edge of the intertidal at Rose Haven, Anne Arundel County MD, and North Point State Park, north of Baltimore Harbor (Fofonoff, unpublished data).
History References - Aikin 1837; Brereton 1830; Brown and Brown 1984; Fernald 1950; Robinson and Fernald 1908; Fernald et al. 1958; Gleason and Cronquist 1991; Gray 1848; Gronovius 1739; Harvill et al. 1992; Kearney 1901; Klotz 1986; Natural Resources Conservation Service 2017; Pursh 1814; Reveal 1983; Simmons et al. 1995
Invasion Comments
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | ||||
| Salinity (‰) | 0.0 | 20.0 | 0.0 | |
| 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 |
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| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
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| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
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| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Dysphania ambrosioides (Mexican Tea) has no known economic impacts in Chesapeake Bay, but it once was reared commercially as a crop in MD and elsewhere as a remedy for parasitic worms (Brown and Brown 1984).
Economic Impacts Outside of Chesapeake Bay
Dysphania ambrosioides (Mexican Tea) was once widely grown as a medicinal herb. 'A strong aromatic tea can be made for those who want it...For some centuries, the oil of C. ambrosioides has had repute in killing intestinal worms and is now much used for hook-worm.' (Fernald et al. 1958). We do not know the extent of current cultivation. This plant does not seem to be widely known as an agricultural weed, but is included on one regional weed list in the USDA 'Plants' database (Natural Resources Conservation Service 2002).
References- Fernald et al. 1958; Natural Resources Conservation Service 2002
Ecological Impacts on Chesapeake Native Species
Dysphania ambrosioides (Mexican Tea) is well-known as a colonizer of disturbed soils (Clemants 1992; Fernald 1950) but does not have known impacts on native biota in intertidal habitats in the Chesapeake Bay region.
References- Clemants 1992; Fernald 1950
Ecological Impacts on Other Chesapeake Non-Native Species
Dysphania ambrosioides (Mexican Tea) is well-known as a colonizer of disturbed soils (Clemants 1992; Fernald 1950) but does not have known impacts on other exotic biota in intertidal habitats in the Chesapeake Bay region.
References- Clemants 1992; Fernald 1950