Xanthium strumarium L. var. canadense
(Mill.) Torr. & A. Gray
The words or terms in red
(actually dark orange) in the text are defined in a
Xanthium strumarium is a native or
adventive plant; it is
native to both Eurasia and North America; it is hard to
distinguish between native and adventive races of this plant.
It is a common summer annual, about 2 to 4 feet tall. It is a
Xanthium strumarium belongs to the
In Greek, ξανθοσ (xanthos)
means yellow, yellowish, greenish, and some say the name Xanthium
was given from the ancient name of some plant, the fruit of which was used
to dye the hair yellow, i.e. blond.
In Latin, struma means scrofula so that
strumarium would mean of or pertaining to the
that leaves retractile and unsightly scars, and the
might then refer to the shape of the fruits.
As for the canadense it is for the
variety quite common in Canada.
Some of the vernacular names of
Xanthium strumarium var. canadense
(and of many other different species or varieties!) are :
Canada Cocklebur, Canada Cockleburr, Cocklebur, Common Cocklebur,
Common Clotbur, Heartleaf Cocklebur, Ogimauwushk,
Sea-burdock, Beach Clotbur, Tumor Cocklebur, Tumor-curing Cocklebur,
Rough Cocklebur and Rough Cockleburr.
Some of the French vernacular names are:
Lampourde, Lampourde de Chine, Glouteron,
Lampourde glouteron and Gratia.
Xanthium strumarium var. canadense has also been known as:
- Xanthium acerosum Greene
- Xanthium californicum Greene
- Xanthium californicum var. rotundifolium Widder
- Xanthium campestre Greene
- Xanthium canadense P. Mill.
- Xanthium cavanillesii Schouw
- Xanthium cenchroides Millsp. & Sherff
- Xanthium commune Britt.
- Xanthium echinatum Murr.
- Xanthium glanduliferum Greene
- Xanthium italicum Moretti
- Xanthium macounii Britt.
- Xanthium oligacanthum Piper
- Xanthium oviforme Wallr.
- Xanthium pensylvanicum Wallr.
- Xanthium saccharatum Wallr.
- Xanthium speciosum Kearney
- Xanthium strumarium ssp. italicum (Moretti) D. Löve
- Xanthium strumarium var. oviforme (Wallr.) M. E. Peck
- Xanthium strumarium var. pensylvanicum (Wallr.)
M. E. Peck
- Xanthium varians Greene
Xanthium strumarium is quite easy to identify by its female flowers
and its fruits that cannot be confused with those of any other plant.
Xanthium strumarium resembles somewhat Arctium minus,
but it has separate male and female flowers that are brownish white and green,
respectively, while the latter species has
perfect flowers with bright pink
The other variety of Xanthium strumarium, the variety glabratum,
bracts that are nearly
glabrous and they tend to be more
oval-shaped and less broad than the bracts of var. canadense.
Otherwise, they are very similar to each other.
The species Xanthium spinosum (Spiny Cocklebur) has
more narrow lanceolate leaves,
and there is a tripartite spine at the base of each leaf
(hence the epithet).
Furthermore, up to now, this species has not been found in Québec.
It is native from South America, but is an adventive in the US,
in New-Brunswick, Ontario and British Columbia.
The root system consists of a taproot
that is stout and rather woody.
- Measuring form 2 to 4 feet.
- Little branched, except for short side stems appearing
from the leaf axils.
- Round or slightly ribbed.
- Often speckled with purple and have short white hairs
scattered across the surface.
- The central stem terminating in a spike-like
raceme of flower heads
that is similar to the racemes of the leaf axils.
- Persisting into winter.
- Up to 8 inches long and 6 inches across.
- Cordate or
with bases that are well-rounded or indented
and tips that are broad and blunt.
or coarsely toothed.
- With an upper surface has a sandpapery texture.
- With a long petiole
that is often reddish or reddish green
and about as long as the leaf
the petioles usually having short white hairs.
- In a single spike-like raceme
that develops from the axil of each upper leaf
and from the central stem,
the racemes being shorter than the petioles of the leaves.
- Each raceme producing several male compound flowers
along its upper half,
while several female compound flowers occur in the lower half.
- The male compound flowers being about 1/4 inch across,
with of numerous staminate florets
that have stamens
with prominent white anthers,
fading quickly after shedding their
- The female compound flowers being up to 1½ inch long and 1 inch across,
each female flower containing 2 pistillate florets,
which are nearly enclosed by a prickly floral bract with a
- The female compound flowers being initially green,
but turn brown as they mature and are slow to detach from the racemes;
they are sessile or have short
- Blooming during the late summer or early fall.
- Pollinated by wind.
- Ovoid (egg-shaped) burr.
- 1 to 3.5 cm long; hard, woody, and covered with hooked spines.
- Each bur containing 2 fruits
(achenes, each with 1 seed.
- Each female flower within the bur-like bract produces a single
that more or less tapers to a point at each end.
- The seeds are often covered with dark membranes.
- One of the seeds in each bur has the capacity
to germinate the following year,
while the the germination of the second seed is delayed
for at least 2 years.
- The spines of the bur help facilitate dispersal,
and burs are buoyant in water.
Cropland (especially corn fields), fallow fields, the floodplain zone of rivers
and ponds, degraded meadows that are poorly drained, dried-up mudholes,
stabilized areas of beaches and sand dunes, vacant lots, and waste areas.
Disturbed, poorly drained areas are preferred.
Xanthium strumarium can be found throughout the United States,
and other temperate areas of the world, from 53 degrees north to 33 degrees
south in latitude.
The canadense variety can be found
throughout all the provinces of Canada.
The map shows the US States where Xanthium strumarium can be found; that
is all the USA but for Alaska and Porto Rico.
Xanthium strumarium has become a noxious weed
worldwide. It invades agricultural lands and can be poisonous to livestock.
Some domestic animals will avoid consuming the plant if other forage is
present, but less discriminating animals, such as pigs, will consume the plants
and then sicken and die. Seedlings and seeds are the most toxic parts of the
The plant also has been used for medicinal properties and for making yellow dye.
Because they readily attach to cloth material, they can be used as darts
in a Xanthium dart game.
Also, sixteen of the spiny burs can be glued together to form a perfect little
The photos of the gallery were taken either with one of the following:
The title in the window shows the date when the picture was taken,
i.e. jan_30_06... would mean that the photo was taken on the 30th of
January, the 06 is for the 6th picture taken that day.
- Fuji Mx 700.
- Minolta DiMAGE 7.
- Nikon 2200.
- EPSON Perfection 1650 scanner.
The month, day and picture number might be followed by a letter:
and if there is no letter it's obviously the Minolta.
- f for the Fuji.
- n for the Nikon.
- s for the EPSON scanner.
Click on the thumbnails to get larger view.
The original photos are usually in TIFF format,
the photos shown are generally in JPEG format,
usually of dimension one half (surface one quarter)
for loading time reduction.
The leaves were scanned at 300 dpi,
and the dimensions of the resulting picture divided by 2 (area divided by 4);
this allows to measure the dimensions of the leaves.
The picture on the left illustrates and open fruit and its two seeds.