Lactuca canadensis

Distribution Map: Based on vouchered plant specimens from wild populations. Cultivated occurrences are not mapped. View county names by placing the cursor over the map.

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Family:	ASTERACEAE
Species:	Lactuca canadensis L.
Common Name:	CANADA LETTUCE
Status:	Native, FACU (NWPL)
Specimen:	View details of USF Herbarium specimens

** Not applicable or data not available.

Classification

Division
Class
Sub Class
Order	ASTERALES
Family	ASTERACEAE
Genus	Lactuca
Species	Lactuca canadensis L. - CANADA LETTUCE

Citation

Citation	LACTUCA CANADENSIS Linnaeus, Syst. Nat., ed. 10. 1193. 1759.
Basionym:	**
Type:	CANADA: Without data, Kalm s.n. (lectotype: LINN 950.7). Lectotypified by Fernald, Rhodora 40: 481. 1938.

** Not applicable or data not available.

Source

County	Herbaria	Literature Citation (If Applicable)
Alachua	FLAS
Baker	USF
Bay	FLAS
Calhoun	USF
Columbia	FLAS
Escambia	USF
Franklin	FSU
Gadsden	USF
Gulf	FSU
Hamilton	FSU
Hernando	USF
Holmes	FLAS
Jackson	FSU
Jefferson	FSU
Lake	USF
Leon	USF
Levy	USF
Liberty	FSU
Madison	FSU
Okaloosa	FLAS
Santa Rosa	FSU
Suwannee	FSU
Taylor	FSU
Wakulla	FLAS
Walton	USF
Washington	FLAS

Synonyms

– Denotes synonyms that are applicable to the state. Show these synonyms only

Synonym	Full Citation	Basionym	Type
Cicerbita canadensis	Cicerbita canadensis (Linnaeus) Wallroth, Sched. Crit. 434. 1822.	BASIONYM: Lactuca canadensis Linnaeus 1759.
Cicerbita elongata	Cicerbita elongata (Muhlenberg ex Willdenow) Wallroth, Sched. Crit. 434. 1822.	BASIONYM: Lactuca elongata Muhlenberg ex Willdenow 1803.
Lactuca canadensis var. elongata	Lactuca canadensis Linnaeus, var. elongata (Muhlenberg ex Willdenow) Farwell, Pap. Michigan Acad. Sci. 2: 46. 1923.	BASIONYM: Lactuca elongata Muhlenberg ex Willdenow 1803.
Lactuca canadensis var. typica	Lactuca canadensis Linnaeus, var. typica Wiegand, Rhodora 22: 10. 1920, nom. inadmiss.	BASIONYM: Lactuca canadensis Linnaeus 1759.
Lactuca elongata	Lactuca elongata Muhlenberg ex Willdenow, Sp. Pl. 3: 1525. 1803.		TYPE: PENNSYLVANIA:
Lactuca elongata var. integrifolia	Lactuca elongata Muhlenberg ex Willdenow, var. integrifolia Chapman, Fl. South. U.S. 252. 1860, non Torrey & A. Gray 1843.		TYPE: "Florida, and northward",
Mulgedium integrifolium	Mulgedium integrifolium Cassini, in Cuvier, Dict. Sci. Nat. 33: 299. 1824, nom. illegit.	BASIONYM: Lactuca canadensis Linnaeus 1759.
Sonchus pallidus	Sonchus pallidus Willdenow, Sp. Pl. 3: 1521. 1803.	BASIONYM: Lactuca canadensis Linnaeus 1759.
Wiestia canadensis	Wiestia canadensis (Linnaeus) Schultz Bipontinus, Jahrb. Pract. Pharm. Verwandte Fächer 4: 155. 1841.	BASIONYM: Lactuca canadensis Linnaeus 1759.
Wiestia elongata	Wiestia elongata (Muhlenberg ex Willdenow) Schultz Bipontinus, Jahrb. Pract. Pharm. Verwandte Fächer 4: 155. 1841.	BASIONYM: Lactuca elongata Muhlenberg ex Willdenow 1803.
Lactuca canadensis forma angustata	Lactuca canadensis Linnaeus, forma angustata Wiegand, Rodhora 22: 11. 1920.		TYPE: CONNECTICUT: Hartford Co.: Southington, 1896, Bissell 333 (holotype: GH).
Lactuca canadensis forma angustipes	Lactuca canadensis Linnaeus, forma angustipes Wiegand, Rhodora 22: 10. 1920.		TYPE: NEW YORK: Cayuga Co.: Sheldrake, 1919, Eames & Wiegand s.n. (holotype: BH?).
Lactuca canadensis forma exauriculata	Lactuca canadensis Linnaeus, forma exauriculata Wiegand, Rhodora 22: 11. 1920.		TYPE: MASSACHUSETTS: Essex Co.: Wenham, s.d., Faxon s.n. (holotype: GH).
Lactuca canadensis forma stenopoda	Lactuca canadensis Linnaeus, forma stenopoda Wiegand, Rhodora 22: 11. 1920.		TYPE: OKLAHOMA: Kay Co.: Stink Creek near Tonkana, 1913, Stevens 1812 (holotype: GH).
Lactuca canadensis forma villicaulis	Lactuca canadensis Linnaeus, forma villicaulis Fernald, Rhodora 41: 574. 1939.		TYPE: VIRGINIA: Dinwiddie Co.: W of Burgess Station, 16 Jul 1938, Fernald & Long 8903 (holotype: GH; isotypes: PH, US).
Lactuca canadensis var. integrifolia	Lactuca canadensis Linnaeus, var. integrifolia (Torrey & A. Gray) A. Gray, Manual, ed. 5. 281. 1869.	BASIONYM: Lactuca elongata Muhlenberg ex Willdenow, var. integrifolia Torrey & A. Gray 1843; Lactuca integrifolia Bigelow 1824, non Nuttall 1818.
Lactuca canadensis var. laciniata	Lactuca canadensis Linnaeus, var. laciniata Farwell, Pap. Michigan Acad. Sci. 2: 45. 1923.		TYPE: MICHIGAN:
Lactuca canadensis var. latifolia	Lactuca canadensis Linnaeus, var. latifolia Kuntze, Revis. Gen. Pl. 1: 349. 1891.
Lactuca canadensis var. longifolia	Lactuca canadensis Linnaeus, var. longifolia (Michaux) Farwell, Pap. Michigan Acad. Sci. 2: 45. 1923.	BASIONYM: Lactuca longifolia Michaux 1803.
Lactuca canadensis var. montana	Lactuca canadensis Linnaeus, var. montana Britton, in Britton & A. Brown, Ill. Fl. N. U.S. 3: 274. 1898.		TYPE: NEW YORK/PENNSYLVANIA:
Lactuca canadensis var. obovata	Lactuca canadensis Linnaeus, var. obovata Wiegand, Rhodora 22: 11. 1920.		TYPE: MASSACHUSETTS: Norfolk Co.: Maugus Hill, Wellesley, 1897, Williams s.n. (holotype: GH).
Lactuca elongata var. integrifolia	Lactuca elongata Muhlenberg ex Willdenow, var. integrifolia Torrey & A. Gray, Fl. N. Amer. 2: 496. 1843.	BASIONYM: Lactuca integrifolia Bigelow 1824, non Nuttall 1818.
Lactuca elongata var. longifolia	Lactuca elongata Muhlenberg ex Willdenow, var. l ongifolia (Michaux) Torrey & A. Gray, Fl. N. Amer. 2: 296. 1843.	BASIONYM: Lactuca longifolia Michaux 1803.
Lactuca integrifolia	Lactuca integrifolia Bigelow, Fl. Boston, ed. 2. 287. 1824, non Nuttall 1818.		TYPE: MASSACHUSETTS:
Lactuca longifolia	Lactuca longifolia Michaux, Fl. Bor.-Amer. 2: 85. 1803.		TYPE: NORTH CAROLINA:
Lactuca sagittifolia	Lactuca sagittifolia Elliott, Sketch Bot. S. Carolina 2: 253. 1823.		TYPE: SOUTH CAROLINA: Richland Co.: Near Columbia,
Lactuca steelei	Lactuca steelei Britton, Man. Fl. N. States 899. 1901.		TYPE: MARYLAND: Montgomery Co.: Chevy Chase, 22 Jul 1897, Steele s.n. (holotype: NY; isotype: US).

Specimens

Country	State	County	Date	Specimen	Notes
USA	Florida	Gadsden Co.	07 Jul 1986	B. F. Hansen 11006
USA	Florida	Leon Co.	30 Jul 1966	D. Laker s.n.
USA	Florida	Baker Co.	11 Jul 1984	B. F. Hansen 10025
USA	Florida	Calhoun Co.	14 Jul 2009	T. MacClendon 932
USA	Florida	Walton Co.	27 Jul 1981	G. Wilhelm 9304
USA	Florida	Escambia Co.	30 Jun 1981	G. Wilhelm 9448
USA	Florida	Hernando Co.	18 Jun 1988	R. Mears s.n.
USA	Florida	Levy Co.	11 Jul 1979	B. F. Hansen 5984	Sheet 2 of 2.
USA	Florida	Levy Co.	11 Jul 1979	B. F. Hansen 5984	Sheet 1 of 2.
USA	Florida	Lake Co.	10 Aug 1986	R. F. Daubenmire s.n.
USA	South Carolina	Allendale Co.	13 May 1956	R. C. Bell 2658
USA	Mississippi	Amite Co.	27 Jun 1956	J. D. Ray, Jr. 6565
USA	South Carolina	Pickens Co.	21 Aug 1989	S. R. Hill 21034
USA	Mississippi	Amite Co.	27 Jun 1956	J. D. Ray, Jr. 6566
USA	Mississippi	Lincoln Co.	26 Jun 1956	J. D. Ray, Jr. s.n.
USA	Georgia	Crisp Co.	04 Jul 1968	R. L. Lane, Jr. 2908
USA	Tennessee	Cocke Co.	04 Aug 1977	P. Genelle 3043
USA	Mississippi	Jefferson Co.	25 Jun 1957	J. D. Ray, Jr. 8323a
USA	Tennessee	Cocke Co.	24 Jul 1977	P. Genelle 2928

Listed Status: Florida

Listed Status:	(Florida):Source - Plants in the Preservation of Native Flora of Florida Act. Chapter 5B-40, Florida Administrative Code. 1998, amended.
Endangered:	A species of plants native to the state that are in imminent danger of extinction within the state, the survival of which is unlikely if the causes of a decline in the number of plants continue, and includes all species determined to be endangered or threatened pursuant to the Federal Endangered Species Act of 1973, as amended.
Threatened:	Listed as Threatened Plants in the Preservation of Native Flora of Florida Act. Defined as species of plants native to the state that are in rapid decline in the number of plants within the state, but which have not so decreased in such number as to cause them to be endangered.

Listed Status: US

Listed Status: US	(U.S.) Source - List of Endangered and Threatened Wildlife and Plants under the provisions of the Endangered Species Act of 1973, as amended.
Endangered:	Any species which is in danger of extinction throughout all or a significant portion of its range.
Threatened:	Any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.

WAP: Wetland AssessmentProcedure

Wetland Assessment Procedure (WAP): Source - Southwest Florida Water Management District, Wetland Assessment Procedure Instruction Manual for Isolated Wetlands (March 2005).

AD:	Adaptive Species. Plant species designated as FAC or Upland by DEP, but commonly seen in the transition zone in limited numbers.
D:	Deep Species. Plant species commonly found in the deep zone, and designated either FAC or OBL by DEP.
OD:	Outer Deep Species. Plant species commonly found in the outer deep zone, and designated either FACW or OBL by DEP.
T:	Transition Species. Plant species commonly found in the transition zone, and designated either FACW or OBL by DEP.
U:	Upland Species. Plant species that are not expected to be seen in wetlands.

ANY - WAP critieria is not taken into consideration
Yes - Show results with WAP designations
No - Show results without WAP designations

FISC: Florida Invasive Species Council

FISC:

Source - Florida Invasive Species Council's 2017 List of Florida's Most Invasive Species

Category I - Species that are invading and disrupting native plant communities in Florida. This definition does not rely on the economic severity or geographic range of the problem, but on the documented ecological damage caused.

Category II - Species that have shown a potential to disrupt native plant communities. These species may become ranked as Category I, but have not yet demonstrated disruption of natural Florida communities.

DEP: Department of Environmental Protection

Wetland Status, Department of Environmental Regulation (DEP): Source - Delineation of the Landward Extent of Wetlands and Surface Waters, Chapter 62-340, Florida Administrative Code. 1994.

OBL:	Obligate wetland. Occurs almost always under natural conditions in wetlands.
FACW:	Facultative Wetland. Usually occurs in wetlands, but occasionally found in non-wetlands
FAC:	Facultative. equally likely to occur in wetlands or non-wetlands.

NWPL: National Wetland Plant List

National Wetland Plant List (NWPL): Source - Lichvar, R.W., M. Butterwick, N.C. Melvin, and W.N. Kirchner. 2014. The National Wetland Plant List: 2014 Update of Wetland Ratings. Phytoneuron 2014-41: 1-42.

OBL:	Obligate Wetland. Occurs almost always (estimated probability 99%) under natural conditions in wetlands.
FACW:	Facultative Wetland. Usually occurs in wetlands (estimated probability 67%-99%), but occasionally found in non-wetlands.
FAC:	Facultative. Equally likely to occur in wetlands or non-wetlands (estimated probability 34%-66%).
FACU:	Facultative Upland. Usually occurs in non-wetlands (estimated probability 67%-99%), but occasionally found in wetlands (estimated probability 1%-33%).
UPL:	Obligate Upland. Occurs in wetlands in another region, but occurs almost always (estimated probability 99%) under natural conditions in non-wetlands in the regions specified.

Persisting

Identifying species that appear as waifs or only periodically appear in the flora for a few seasons.

Any - Persisting critieria is not taken into consideration
Yes - Show results with a Persisting value of Y
No - Show results without Persisting value of N

Duration

Annual:	Plants that perform their entire lifecycle within a single growing season. All roots, stems, and leaves die at the end of the growing season. Over wintering seeds allow the next generation to appear.
Biennial:	A plant that is typically vegetative its first year and blooms the following season. Once it has bloomed and set seed, the plant dies. Garlic mustard is an example of a biennial.
Perennial:	These plants live for three or more seasons. Many perennials may not be mature enough to bloom during its first year. Perennial wildflowers re-grow each season from overwinter root material.

Category

Vascular:	Any of various plants that have the vascular tissues xylem and phloem. The vascular plants include all seed-bearing plants (the gymnosperms and angiosperms) and the pteridophytes (including the ferns, lycophytes, and horsetails). Also called tracheophyte.
Bryophyte:	A large group of seedless green plants including the mosses, liverworts, and hornworts. Bryophytes lack the specialized tissues xylem and phloem that circulate water and dissolved nutrients in the vascular plants. Bryophytes generally live on land but are mostly found in moist environments, for they have free-swimming sperm that require water for transport. In contrast to the vascular plants, the gametophyte (haploid) generation of bryophytes constitutes the larger plant form, while the small sporophyte (diploid) generation grows on or within the gametophyte and depends upon it for nutrition.
Lichen:	The mutualistic symbiotic association of a fungus with an alga or a cyanobacterium, or both. The fungal component of a lichen absorbs water and nutrients from the surroundings and provides a suitable environment for the alga or cyanobacterium. These live protected among the dense fungal hyphae and produce carbohydrates for the fungus by photosynthesis. Owing to this partnership, lichens can thrive in harsh environments such as mountaintops and polar regions. The more familiar lichens grow slowly as crusty patches, but lichens are found in a variety of forms, such as the tall, plantlike reindeer moss. The association between the different organisms in a lichen is so close that lichens are routinely referred to as a single organism, and scientists classify lichens using the name of the fungal component.

(Definitions from: American Heritage Science Dictionary)

Growth Habit

Intro paragraph to be provided by New York.

Vine:	DESCRIPTION TO BE PROVIDED BY NEW YORK.
Shrub:	DESCRIPTION TO BE PROVIDED BY NEW YORK.
Tree:	DESCRIPTION TO BE PROVIDED BY NEW YORK.
Et cetera:	DESCRIPTION TO BE PROVIDED BY NEW YORK.

State Rank

This numeric rank provides the relative rarity for each species based on a scale from 1 (very rare) to 5 (common). These ranks carry no legal status.

S1 - Typically 5 or fewer occurrences, very few remaining individuals, acres, or miles of stream, or some factor of its biology making it especially vulnerable in the state.
S2 - Typically 6 to 20 occurrences, few remaining individuals, acres, or miles of stream, or factors demonstrably making it very vulnerable in the state.
S3 - Typically 21 to 100 occurrences, limited acreage, or miles of stream in the state.
S4 - Apparently secure in the state.
S5 - Demonstrably secure in the state.
SE - State exotic or non-native.
SH - Historically known from the state, but not seen in the past 15 years.
SNA - Species for which a rank is not applicable. This is mainly those species which are now excluded from flora for various reasons.
SNR - Not yet ranked.
SX - Apparently extirpated from the state.

Global Rank

Each species' global rank is determined by NatureServe. These ranks carry no legal weight. The global rank reflects the species worldwide rarity.

G1 - Critically imperiled globally because of extreme rarity (5 or fewer occurrences), or very few remaining acres, or miles of stream) or especially vulnerable to extinction because of some factor of its biology.
G2 - Imperiled globally because of rarity (6 - 20 occurrences, or few remaining acres, or miles of stream) or very vulnerable to extinction throughout its range because of other factors.
G3 - Imperiled globally because of rarity (6 - 20 occurrences, or few remaining acres, or miles of stream) or very vulnerable to extinction throughout its range because of other factors.
G4 - Imperiled globally because of rarity (6 - 20 occurrences, or few remaining acres, or miles of stream) or very vulnerable to extinction throughout its range because of other factors.
G5 - Demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.
GH - Historically known, with the expectation that it might be rediscovered.
GNA - Species for which a rank is not applicable. NatureServe does not typically rank hybrid species.
GNR - Not yet ranked.
GX - Species believed to be extinct.

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Filter by County - Counties to Exclude - ANY versus ALL

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Associated Ecological Communities

View a List of All Ecological Communities

For more information, contact: Richard Wunderlin or Bruce Hansen, Alan Franck, or Karla Alvarado

Web Development: USF Water Institute

A member of the University of South Florida family of PlantAtlas.org websites

Citation Information:

Wunderlin, R. P., B. F. Hansen, A. R. Franck, and F. B. Essig. 2025. Atlas of Florida Plants (http://florida.plantatlas.usf.edu/). [S. M. Landry and K. N. Campbell (application development), USF Water Institute.] Institute for Systematic Botany, University of South Florida, Tampa.

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Definition: Vouchered Specimen

A voucher specimen is a pressed and thoroughly dried plant sample deposited in a herbarium, and is intended to be a permanent record supporting research purposes. A voucher may be a record of a plant's occurrence in a particular area, or a specific example of a plant used in a scientific investigation.

Proper vouchers display all the necessary attributes for complete identification of the plant, and are to be accompanied by accurate locality, habitat, collection time, and collector data.

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