common burdock (Arctium minus)
Arcion minus Bubani
Arctium chabertii Briq. & Cavill.
Arctium conglomeratum Schur ex Nyman
Arctium euminus Syme
Arctium lappa Kalm
Arctium montanum Steud.
Arctium pubens Bab.
Bardana minor Hill
Lappa minor Hill
Lappa pubens (Bab.) Boreau
CONFIRMATION STATUS: Pending confirmation.
TAXONOMY: The currently accepted scientific name of common bur-
dock is Arctium minus Bernh. Arctium minus is a complex species with
many variants that have been recognized at ranks ranging from forma to
species. Some North American researchers have often distinguished plants
with involucres more than 3 cm diameter that equal or overtop the corollas
as Arctium nemorosum. Others have treated those plants as a subspecies of
Arctium minus. Some European botanists have recognized Arctium
nemorosum as a species distinct from Arctium minus, with a different
and more restricted circumscription than that used by North American
workers. Some American authors have taken up the name Arctium vulgare
in place of Arctium nemorosum and applied Arctium vulgare (dubbed
woodland burdock) to the larger-headed North American plants. Arctium
minus is the only recognized species of burdock recorded as occurring in
NATIVE STATUS: Introduced, United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS:
Habit: This adventive biennial plant is a low-growing rosette of basal
leaves during the first year, but during the second year it becomes 3-6' tall.
The second-year plant is little branched below, but produces short flower-
ing side stems above. The stems are rather stout, round or slightly ridged
in circumference, and light green to slightly reddish green. Young stems
are covered with white cobwebby hairs, but older stems become glabrous
and have conspicuous longitudinal veins.
Leaves: The basal leaves are up to 2' long and 1½' across. They have long
petioles and resemble the leaves of rhubarb to some extent. The lower
leaves of second year plants resemble the basal leaves, except that they are somewhat smaller. These leaves are ovate-cordate, dull green above, and
whitish green below, with blunt tips. They are nearly glabrous above, but
finely pubescent below. Their margins are somewhat undulate, crisped, or
smooth, sometimes with a few blunt teeth. Their long petioles have a con-
spicuous furrow above and they are usually hollow inside. The middle to
upper leaves of second year plants are similar in appearance, but they are
smaller in size and more likely to be ovate with margins that are more
smooth and petioles that are shorter.
Flowers: The upper stems terminate in small clusters of flowerheads on
short stalks. Each flowerhead is about ¾-1" across, consisting of numerous
disk florets and floral bracts that have narrow hooked tips. There are no
ray florets. Each disk floret has a corolla that is narrowly cylindrical with
5 slender upright lobes at the apex. The disk florets are usually some shade
of pink or purple, although a rare form of common burdock with white
florets occurs. The slender white style is strongly exerted from the corolla
and bifurcated at its tip. The dark purple anthers form a sheath around the
style that lies just above the lobes of the corolla. The abundant bracts are
green at the base, but become yellowish green toward the their hooked tips.
They have a spiny appearance and have few, if any, cobwebby hairs in their
Fruit/Seeds: The achenes are oblong, broader and more truncate at one
end than the other, and light brown with dark brown speckles. At the apex,
each achene has a crown of fine bristles, but these are deciduous and soon
fall off. The floral bracts turn brown and enclose the withered flowers at
the top, forming a bur. The burs are persistent and remain on the stalks af-
ter the leaves have withered away during the fall.
Roots: The root system consists of a stout taproot that runs deep into the
REGENERATION PROCESS: This plant spreads by reseeding itself,
and often forms colonies of variable size.
HABITAT TYPES: It is adventive from Northern Europe and also oc-
curs in Asia. Habitats include woodland edges, savannas, thickets, pas-
tures, edges of fields and fence rows, weedy meadows, barnyards, areas
along roads and railroads, and waste areas. Disturbed areas are preferred,
although it occasionally appears in more pristine natural areas, particular-
ly along paths and animal trails.
SITE CHARACTERISTICS: Common burdock is often found in full or
partial sun, slightly moist to mesic conditions, and a loamy fertile soil. It
has a robust nature and can be found in other kinds of soil and drier
conditions. It is often aggressive.
SEASONAL DEVELOPMENT: The blooming period occurs from mid-
summer to early fall, and lasts about a month for a colony of plants.
GENERAL DISTRIBUTION: Common burdock has been reported from
every state in the United States (with the exception of Florida and Hawaii),
and from all the southern Canadian provinces (excepting Newfoundland).
SKY MEADOWS DISTRIBUTION: To be determined.
IMPORTANCE AND USES: The flowers are pollinated primarily by
long-tongued bees, including bumblebees, honeybees, miner bees, and
leaf-cutting bees, which suck nectar and collect pollen. Other visitors
include bee flies, butterflies, and skippers, which seek nectar and are
also effective at pollination. The caterpillars of several Papaipema spp.
(borer moths) bore through the pith of the stems, including Papaipema
cataphracta (burdock borer moth), Papaipema arctivorens (northern
burdock borer moth), and Papaipema rigida (rigid sunflower borer
moth). The foliage of common burdock is one of the food sources for the
caterpillars of the butterfly Vanessa cardui (painted lady). The ring-
necked pheasant eats the seeds to a limited extent. Because the foliage
is bitter-tasting, common burdock is not a preferred food plant for mam-
malian herbivores, although livestock and deer will browse on it if nothing
else is available. There is some evidence that the foliage may be toxic to
rabbits. The seeds are distributed far and wide by animals and humans
because the burs cling readily to fur and clothing. They are quite difficult
The stout taproot has a sweet taste and can be used as food. Similarly, if
the outer husk of the stems are peeled away, the pith can be used like a
Crooked Run Valley