Lactuca canadensis
L.
Asteraceae
Agathyrsus acuminatus (Willd.) Sweet
Cicerbita canadensis Wallr.
Cicerbita elongata Wallr.
Galathenium elongatum Nutt.
Galathenium integrifolium Nutt.
Galathenium salicifolium Nutt.
Lactuca caroliniana Walter
Lactuca elongata Mulh. ex Willd.
Lactuca longifolia Michx.
Lactuca procera Schrad. ex DC.
Lactuca sagittifolia Elliott
Lactuca steelei Britton
Lactuca villosa Muhl. ex Torr. & A.Gray
Mulgedium integrifolium Cass.
Sonchus acuminatus Willd.
Sonchus pallidus Willd.
Wiestia canadensis Sch.Bip.
Wiestia elongata Sch.Bip.
Common Name: Canada Lettuce
General Information
Lactuca canadensis is a biennial plant growing from a taproot. It produces a basal rosette of leaves and a single, branched flowering stem that grows from 15 - 450cm or more tall but is usually between 40 - 200cm[
270- Title
- Flora of N. America
- Publication
-
- Author
-
- Website
- http://flora.huh.harvard.edu/fna/
- Publisher
-
- Year
- 0
- ISBN
-
- Description
- An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
].
Known Hazards
Although no specific mention of toxicity has been seen for this species, many plants in this genus contain a narcotic principle, this is at its most concentrated when the plant begins to flower. This principle has been almost bred out of the cultivated forms of lettuce but is produced when the plant starts to go to seed[
13- Title
- Hamlyn Encyclopaedia of Plants.
- Publication
-
- Author
- Triska. Dr.
- Publisher
- Hamlyn
- Year
- 1975
- ISBN
- 0-600-33545-3
- Description
- Very interesting reading, giving some details of plant uses and quite a lot of folk-lore.
].
Botanical References
1- Title
- RHS Dictionary of Plants plus Supplement. 1956
- Publication
-
- Author
- F. Chittendon.
- Publisher
- Oxford University Press
- Year
- 1951
- ISBN
- -
- Description
- Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [200]).
,
43- Title
- Gray's Manual of Botany.Eighth Edition
- Publication
-
- Author
- Fernald. M. L.
- Publisher
- American Book Co.; New York
- Year
- 1950
- ISBN
- 0442222505
- Description
- A bit dated but a good and concise flora of the eastern part of N. America.
,
235- Title
- An Illustrated Flora of the Northern United States and Canada
- Publication
-
- Author
- Britton. N. L. Brown. A.
- Publisher
- Dover Publications. New York.
- Year
- 1970
- ISBN
- 0-486-22642-5
- Description
- Reprint of a 1913 Flora, but still a very useful book.
,
270- Title
- Flora of N. America
- Publication
-
- Author
-
- Website
- http://flora.huh.harvard.edu/fna/
- Publisher
-
- Year
- 0
- ISBN
-
- Description
- An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
Range
N. America - Yukon, British Columbia to Quebec, south to California, Texas and Florida; Caribbean - Hispaniola
Habitat
Thickets, woodland borders and clearings[
43- Title
- Gray's Manual of Botany.Eighth Edition
- Publication
-
- Author
- Fernald. M. L.
- Publisher
- American Book Co.; New York
- Year
- 1950
- ISBN
- 0442222505
- Description
- A bit dated but a good and concise flora of the eastern part of N. America.
]. Moist open places[
235- Title
- An Illustrated Flora of the Northern United States and Canada
- Publication
-
- Author
- Britton. N. L. Brown. A.
- Publisher
- Dover Publications. New York.
- Year
- 1970
- ISBN
- 0-486-22642-5
- Description
- Reprint of a 1913 Flora, but still a very useful book.
]. Usually found in sandy soils[
274- Title
- Illustrated Flora of North Central Texas
- Publication
-
- Author
- Diggs, Jnr. G.M.; Lipscomb. B. L. & O'Kennon. R. J
- Website
- http://artemis.austincollege.edu/acad/bio/gdiggs/NCTXpdf.htm
- Publisher
- Botanical Research Institute, Texas.
- Year
- 1999
- ISBN
- 1-889878-01-4
- Description
- An excellent flora, which is also available on-line.
]. Roadsides, swamps, salt marshes, thickets; at from sea level to 2200 metres[
270- Title
- Flora of N. America
- Publication
-
- Author
-
- Website
- http://flora.huh.harvard.edu/fna/
- Publisher
-
- Year
- 0
- ISBN
-
- Description
- An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
].
Properties
| Weed Potential | Yes |
| Edibility Rating |  |
| Medicinal Rating |  |
| Habit | Biennial |
| Height | 1.50 m |
| Pollinators | Insects |
| Cultivation Status | Wild |
Cultivation Details
Prefers a light sandy loam[
1- Title
- RHS Dictionary of Plants plus Supplement. 1956
- Publication
-
- Author
- F. Chittendon.
- Publisher
- Oxford University Press
- Year
- 1951
- ISBN
- -
- Description
- Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [200]).
].
Hybridizes in the wild with L. ludoviciana and the two species can sometimes be difficult to separate[
274- Title
- Illustrated Flora of North Central Texas
- Publication
-
- Author
- Diggs, Jnr. G.M.; Lipscomb. B. L. & O'Kennon. R. J
- Website
- http://artemis.austincollege.edu/acad/bio/gdiggs/NCTXpdf.htm
- Publisher
- Botanical Research Institute, Texas.
- Year
- 1999
- ISBN
- 1-889878-01-4
- Description
- An excellent flora, which is also available on-line.
].
Edible Uses
Young leaves and stems - raw or cooked[
46- Title
- Dictionary of Economic Plants.
- Publication
-
- Author
- Uphof. J. C. Th.
- Publisher
- Weinheim
- Year
- 1959
- ISBN
- -
- Description
- An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
,
55- Title
- Eat the Weeds.
- Publication
-
- Author
- Harris. B. C.
- Publisher
- Pivot Health
- Year
- 1973
- ISBN
- -
- Description
- Interesting reading.
,
61- Title
- A Dictionary of Plants Used by Man.
- Publication
-
- Author
- Usher. G.
- Publisher
- Constable
- Year
- 1974
- ISBN
- 0094579202
- Description
- Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
,
85- Title
- Edible Native Plants of the Rocky Mountains.
- Publication
-
- Author
- Harrington. H. D.
- Publisher
- University of New Mexico Press
- Year
- 1967
- ISBN
- 0-8623-0343-9
- Description
- A superb book. Very readable, it gives the results of the authors experiments with native edible plants.
,
105- Title
- Tanaka's Cyclopedia of Edible Plants of the World.
- Publication
-
- Author
- Tanaka. T. & Nakao S.
- Publisher
- Keigaku Publishing; Tokyo
- Year
- 1976
- ISBN
- -
- Description
- The most comprehensive list of edible plants I've come across. Only the briefest entry for each species, though, and some of the entries are more than a little dubious. Not for the casual reader.
,
177- Title
- Plants for Human Consumption.
- Publication
-
- Author
- Kunkel. G.
- Publisher
- Koeltz Scientific Books
- Year
- 1984
- ISBN
- 3874292169
- Description
- An excellent book for the dedicated. A comprehensive listing of Latin names with a brief list of edible parts.
,
1438- Title
- Food Plants in the Americas: A Survey of the Domesticated, Cultivated, and Wild Plants Used for Human Food in North,
- Publication
-
- Author
- Kermath B.M.; Bennett B.C.' Pulsipher L.M.
- Publisher
-
- Year
- 2014
- ISBN
-
- Description
- A pre-publication draft of an amazing, on-going work first started in 1985. It contains information on more than 3,900 taxa from the Americas - from Arctic regions to the Tropics
]. Cooked and eaten as greens[
257- Title
- Native American Ethnobotany
- Publication
-
- Author
- Moerman. D.
- Publisher
- Timber Press. Oregon.
- Year
- 1998
- ISBN
- 0-88192-453-9
- Description
- Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
].
Medicinal
The whole plant is rich in a milky sap that flows freely from any wounds. This hardens and dries when in contact with the air[
4- Title
- A Modern Herbal.
- Publication
-
- Author
- Grieve.
- Publisher
- Penguin
- Year
- 1984
- ISBN
- 0-14-046-440-9
- Description
- Not so modern (1930's?) but lots of information, mainly temperate plants.
]. The sap contains 'lactucarium', which is used in medicine for its anodyne, antispasmodic, digestive, diuretic, hypnotic, narcotic and sedative properties[
9- Title
- Edible and Medicinal Plants.
- Publication
-
- Author
- Launert. E.
- Publisher
- Hamlyn
- Year
- 1981
- ISBN
- 0-600-37216-2
- Description
- Covers plants in Europe. a drawing of each plant, quite a bit of interesting information.
,
21- Title
- The Herb Book.
- Publication
-
- Author
- Lust. J.
- Publisher
- Bantam books
- Year
- 1983
- ISBN
- 0-553-23827-2
- Description
- Lots of information tightly crammed into a fairly small book.
,
46- Title
- Dictionary of Economic Plants.
- Publication
-
- Author
- Uphof. J. C. Th.
- Publisher
- Weinheim
- Year
- 1959
- ISBN
- -
- Description
- An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
,
165- Title
- The Dictionary of Modern Herbalism.
- Publication
-
- Author
- Mills. S. Y.
- Publisher
-
- Year
-
- ISBN
-
- Description
- An excellent small herbal.
,
192- Title
- Narcotic Plants
- Publication
-
- Author
- Emboden. W.
- Publisher
- Studio Vista
- Year
- 1979
- ISBN
- 0-289-70864-8
- Description
- A lot of details about the history, chemistry and use of narcotic plants, including hallucinogens, stimulants, inebriants and hypnotics.
,
207- Title
- The History and Folklore of North American Wild Flowers.
- Publication
-
- Author
- Coffey. T.
- Publisher
- Facts on File.
- Year
- 1993
- ISBN
- 0-8160-2624-6
- Description
- A nice read, lots of information on plant uses.
,
213- Title
- Earth Medicine, Earth Food.
- Publication
-
- Author
- Weiner. M. A.
- Publisher
- Ballantine Books
- Year
- 1980
- ISBN
- 0-449-90589-6
- Description
- A nice book to read though it is difficult to look up individual plants since the book is divided into separate sections dealing with the different medicinal uses plus a section on edible plants. Common names are used instead of botanical.
,
222- Title
- A Field Guide to Medicinal Plants. Eastern and Central N. America.
- Publication
-
- Author
- Foster. S. & Duke. J. A.
- Publisher
- Houghton Mifflin Co.
- Year
- 1990
- ISBN
- 0-395-46722-5
- Description
- A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
,
238- Title
- Encyclopaedia of Herbs and their Uses.
- Publication
-
- Author
- Bown. D.
- Publisher
- Dorling Kindersley, London.
- Year
- 1995
- ISBN
- 0-7513-020-31
- Description
- A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
]. Lactucarium has the effects of a feeble opium, but without its tendency to cause digestive upsets[
4- Title
- A Modern Herbal.
- Publication
-
- Author
- Grieve.
- Publisher
- Penguin
- Year
- 1984
- ISBN
- 0-14-046-440-9
- Description
- Not so modern (1930's?) but lots of information, mainly temperate plants.
], nor is it addictive[
7- Title
- Encyclopaedia of Medicinal Plants.
- Publication
-
- Author
- Chiej. R.
- Publisher
- MacDonald
- Year
- 1984
- ISBN
- 0-356-10541-5
- Description
- Covers plants growing in Europe. Also gives other interesting information on the plants. Good photographs.
]. It is taken internally in the treatment of insomnia, anxiety, neuroses, hyperactivity in children, dry coughs, whooping cough, rheumatic pain etc[
238- Title
- Encyclopaedia of Herbs and their Uses.
- Publication
-
- Author
- Bown. D.
- Publisher
- Dorling Kindersley, London.
- Year
- 1995
- ISBN
- 0-7513-020-31
- Description
- A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
]. Concentrations of lactucarium are low in young plants and most concentrated when the plant comes into flower[
238- Title
- Encyclopaedia of Herbs and their Uses.
- Publication
-
- Author
- Bown. D.
- Publisher
- Dorling Kindersley, London.
- Year
- 1995
- ISBN
- 0-7513-020-31
- Description
- A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
]. It is collected commercially by cutting the heads of the plants and scraping the juice into china vessels several times a day until the plant is exhausted[
4- Title
- A Modern Herbal.
- Publication
-
- Author
- Grieve.
- Publisher
- Penguin
- Year
- 1984
- ISBN
- 0-14-046-440-9
- Description
- Not so modern (1930's?) but lots of information, mainly temperate plants.
]. An infusion of the fresh or dried flowering plant can also be used[
9- Title
- Edible and Medicinal Plants.
- Publication
-
- Author
- Launert. E.
- Publisher
- Hamlyn
- Year
- 1981
- ISBN
- 0-600-37216-2
- Description
- Covers plants in Europe. a drawing of each plant, quite a bit of interesting information.
].
The plant should be used with caution, and never without the supervision of a skilled practitioner. Even normal doses can cause drowsiness whilst excess causes restlessness[
238- Title
- Encyclopaedia of Herbs and their Uses.
- Publication
-
- Author
- Bown. D.
- Publisher
- Dorling Kindersley, London.
- Year
- 1995
- ISBN
- 0-7513-020-31
- Description
- A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
] and overdoses can cause death through cardiac paralysis[
7- Title
- Encyclopaedia of Medicinal Plants.
- Publication
-
- Author
- Chiej. R.
- Publisher
- MacDonald
- Year
- 1984
- ISBN
- 0-356-10541-5
- Description
- Covers plants growing in Europe. Also gives other interesting information on the plants. Good photographs.
,
9- Title
- Edible and Medicinal Plants.
- Publication
-
- Author
- Launert. E.
- Publisher
- Hamlyn
- Year
- 1981
- ISBN
- 0-600-37216-2
- Description
- Covers plants in Europe. a drawing of each plant, quite a bit of interesting information.
].
Some physicians believe that any effects of this medicine are caused by the mind of the patient rather than by the medicine[
213- Title
- Earth Medicine, Earth Food.
- Publication
-
- Author
- Weiner. M. A.
- Publisher
- Ballantine Books
- Year
- 1980
- ISBN
- 0-449-90589-6
- Description
- A nice book to read though it is difficult to look up individual plants since the book is divided into separate sections dealing with the different medicinal uses plus a section on edible plants. Common names are used instead of botanical.
].
The sap has also been applied externally in the treatment of warts[
222- Title
- A Field Guide to Medicinal Plants. Eastern and Central N. America.
- Publication
-
- Author
- Foster. S. & Duke. J. A.
- Publisher
- Houghton Mifflin Co.
- Year
- 1990
- ISBN
- 0-395-46722-5
- Description
- A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
].
Other Uses
None known
Propagation
Seed - sow spring in situ and only just cover the seed. Germination is usually fairly quick.
If you have any useful information about this plant, please leave a comment. Comments have to be approved before they are shown here.
Useful Temperate Plants Database 2016 by
Ken Fern,
web interface by
Ajna Fern
with help from
Richard Morris.
