NVCS

A3849 Conyza canadensis - Cirsium arvense - Lactuca serriola Ruderal Wet Meadow Alliance

Type Concept Sentence: This alliance covers those non-native forb-dominated waste and other disturbed places of the western U.S. dominated by such species as Conyza canadensis, Cirsium arvense, or Lactuca serriola (other species may be present to dominant).

Common (Translated Scientific) Name: Canadian Horseweed - Canada Thistle - Prickly Lettuce Ruderal Wet Meadow Alliance

Colloquial Name: Western Ruderal Forb Wet Meadow

Hierarchy Level: Alliance

Type Concept: This alliance covers herbaceous areas dominated by non-native forb species such as Conyza canadensis, Cirsium arvense, or Lactuca serriola. Many other facultative wet forbs may be present or dominant, such as Chenopodium album, Dipsacus fullonum, Lepidium perfoliatum, Rumex crispus, Sisymbrium altissimum, Sonchus arvensis, and many others. These disturbed places are generally seasonally or intermittently flooded, usually drying completely between wet episodes. They are generally not alkaline but may be mildly so. It is found throughout the western U.S.

Diagnostic Characteristics: Disturbed areas dominated by one or a mix of non-native wetland or facultative forb species such as Chenopodium album, Cirsium arvense, Conyza canadensis, Dipsacus fullonum, Lactuca serriola, Lepidium perfoliatum, Rumex crispus, Sisymbrium altissimum, or Sonchus arvensis.

Rationale for Nominal Species or Physiognomic Features: No Data Available

Classification Comments: This alliance covers western U.S. mesic to seasonally wet to moist areas, not dry upland areas.

Similar NVC Types: No Data Available

note: No Data Available

Physiognomy and Structure: Broad-leaved annual or perennial herbaceous stands <2 m in height.

Floristics: These stands are dominated by non-native forb species such as Conyza canadensis, Cirsium arvense, or Lactuca serriola. Many other facultative wet forbs may be present or dominant, such as Chenopodium album, Cirsium arvense, Conyza canadensis, Dipsacus fullonum, Lactuca serriola, Lepidium perfoliatum, Rumex crispus, Sisymbrium altissimum, Sonchus arvensis, and many others. Other commonly associated forbs present and contributing low to moderate cover include Melilotus officinalis, Rorippa palustris ssp. hispida, Salsola tragus, and Verbascum thapsus. Some graminoids such as Hordeum jubatum may also be present, but these tend to be not as abundant as the total forb cover.

Dynamics: This alliance is generally a product of serious soil disturbance in areas that are periodically wet, such as abandoned fields within flood zones or high water areas or drawn down reservoirs, or rings around stock ponds.

Environmental Description: These alliance occur in mesic areas that are somehow disturbed, and are common throughout western North America. Stands occur in reservoir drawdown zones, disturbed areas near streams or old fields, and heavily damaged soils near open water.

Geographic Range: This alliance is found throughout the western U.S.

Nations: US

States/Provinces: AZ, CA, CO, ID, MT, NM, NV, OR, UT, WA

Plot Analysis Summary: http://vegbank.org/natureserve/ELEMENT_GLOBAL.2.899901

Confidence Level: Low

Confidence Level Comments: No Data Available

Grank: GNA

Greasons: No Data Available

Type	Name	Database Code	Classification Code
Class	2 Shrub & Herb Vegetation Class	C02	2
Subclass	2.C Shrub & Herb Wetland Subclass	S44	2.C
Formation	2.C.4 Temperate to Polar Freshwater Marsh, Wet Meadow & Shrubland Formation	F013	2.C.4
Division	2.C.4.Nb Western North American Temperate Freshwater Marsh, Wet Meadow & Shrubland Division	D031	2.C.4.Nb
Macrogroup	2.C.4.Nb.90 Western North American Ruderal Marsh, Wet Meadow & Shrubland Macrogroup	M301	2.C.4.Nb.90
Group	2.C.4.Nb.90.a Kentucky Bluegrass - Canadian Horseweed - Canada Thistle Ruderal Marsh, Wet Meadow & Shrubland Group	G524	2.C.4.Nb.90.a
Alliance	A3849 Canadian Horseweed - Canada Thistle - Prickly Lettuce Ruderal Wet Meadow Alliance	A3849	2.C.4.Nb.90.a
Association	CEGL002800 Canadian Horseweed Ruderal Wet Meadow	CEGL002800	2.C.4.Nb.90.a

Concept Lineage: No Data Available

Predecessors: No Data Available

Obsolete Names: No Data Available

Obsolete Parents: No Data Available

Synonomy: No Data Available

Concept Author(s): G. Kittel, in Faber-Langendoen et al. (2013)

Author of Description: G. Kittel

Acknowledgements: No Data Available

Version Date: 01-07-14

Faber-Langendoen, D., J. Drake, M. Hall, G. Kittel, S. Menard, C. Nordman, M. Pyne, M. Reid, M. Russo, K. Schulz, L. Sneddon, K. Snow, and J. Teague. 2013-2019b. Screening alliances for induction into the U.S. National Vegetation Classification: Part 1 - Alliance concept review. NatureServe, Arlington, VA.