Apparently, 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 vegetable. There are 3 Arctium spp. (Burdocks) in Illinois. One of them, Arctium tomentosum (Woolly Burdock) has abundant cobwebby hairs that cover the floral bracts below their hooked tips. Another species, Arctium lappa (Great Burdock), is often taller than Common Burdock, and it has larger flowerheads about 1–1½' across. The flowerheads of Great Burdock have longer stalks and they are arranged in flat-headed cymes, whereas the flowerheads of Common Burdock are more vertically bunched together on short stalks, as revealed in the upper photograph. The petioles of the lower leaves in Great Burdock are less furrowed on the upper surface and they are solid inside, rather than hollow.

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 flowering 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. 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 conspicuous 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.  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 midst. The blooming period occurs from mid-summer to early fall, and lasts about a month for a colony of plants. 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 after the leaves have withered away during the fall. The root system consists of a stout taproot that runs deep into the ground. This plant spreads by reseeding itself, and often forms colonies of variable size.

Arctium minus (Hill) Bernh.:
Canada (North America)
Chile (South America)
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Plants to 50–300 cm. Basal leaves: petioles hollow (sometimes only at base), 15–50 cm, thinly to densely cobwebby; blades 30–60 × 15–35 cm, coarsely dentate to subentire (rarely deeply dissected), abaxially ± thinly gray-tomentose, adaxially green, sparsely short-hairy. Heads in racemiform or paniculiform clusters, sessile to pedunculate. Peduncles 0–9.5 cm. Involucres 15–40 mm diam. Phyllaries linear to linear-lanceolate, glabrous to densely cobwebby, inner often purplish tinged, margins often minutely serrate with fine teeth, puberulent with glandular and or eglandular hairs. Florets 30+; corollas purple, pink, or white, 7.5–12 mm, glabrous or limb glandular-puberulent. Cypselae dark brown or with darker spots, 5–8 mm; pappus bristles 1–3.5 mm. 2n = 32 (Germany), 36 (as A. nemorosum).

Lappa minor Hill, Veg. Syst. 4: 28. 1762

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 mammalian 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 to remove. Photographic Location

Arctium minus (Common Burdock) introduced
(Bees suck nectar or collect pollen, other insects suck nectar; one observation is from Hilty, otherwise observations are from Robertson)

Bees (long-tongued)
Apidae (Apinae): Apis mellifera sn; Apidae (Bombini): Bombus impatiens sn cp, Bombus pensylvanica sn cp, Bombus vagans sn; Anthophoridae (Ceratinini): Ceratina dupla dupla sn cp; Anthophoridae (Eucerini): Melissodes bimaculata bimaculata sn, Melissodes denticulata sn; Megachilidae (Megachilini): Megachile centuncularis sn cp, Megachile inimica sayi sn cp

Bees (short-tongued)
Halictidae (Halictinae): Agapostemon sericea sn, Halictus ligatus sn, Halictus rubicunda sn, Lasioglossum imitatus cp np

Flies
Syrphidae: Eristalis tenax sn; Bombyliidae: Exoprosopa fasciata sn

Butterflies
Pieridae: Colias philodice sn, Pieris rapae sn; Papilionidae: Papilio troilus (H)

Skippers
Hesperiidae: Polites themistocles sn, Pyrgus communis sn

In Great Britain and/or Ireland:
Foodplant / saprobe
fruitbody of Ceriporiopsis herbicola is saprobic on dead stem of Arctium minus

Foodplant / saprobe
effuse colony of Cylindrotrichum dematiaceous anamorph of Cylindrotrichum oligospermum is saprobic on dead stem of Arctium minus
Remarks: season: 4-9

Foodplant / saprobe
fruitbody of Lindtneria leucobryophila is saprobic on dead stem of Arctium minus

Foodplant / miner
larva (young) of Melanagromyza lappae mines leaf -> midrib -> stem of Arctium minus

Foodplant / miner
larva of Phytomyza lappae mines leaf of Arctium minus

Foodplant / saprobe
effuse colony of Pseudospiropes dematiaceous anamorph of Pseudospiropes rousselianus is saprobic on dead stem of Arctium minus

Foodplant / saprobe
effuse colony of Stachybotrys dematiaceous anamorph of Stachybotrys cylindrospora is saprobic on dead stem of Arctium minus
Remarks: season: 5-9
Other: minor host/prey

Foodplant / gall
larva of Tephritis bardanae causes gall of capitulum of Arctium minus
Remarks: season: -8

Foodplant / internal feeder
larva of Terellia tussilaginis feeds within achene of Arctium minus
Remarks: season: 9

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 4
Specimens with Barcodes: 15
Species With Barcodes: 1

Canada

Rounded National Status Rank: NNA - Not Applicable

Rounded Global Status Rank: GNR - Not Yet Ranked

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

Rounded Global Status Rank: GNR - Not Yet Ranked

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. Range & Habitat

Arctium minus has been reported from Delaware and Texas; I have not seen specimens.

Arctium minus is a complex species with many variants that have been recognized at ranks ranging from forma to species (J. Arènes 1950). Some North American workers (e.g., R. J. Moore and C. Frankton 1974) have often distinguished plants with involucres more than 3 cm diameter that equal or overtop the corollas as A. nemorosum. Arènes treated those plants as a subspecies of A. minus. Arctium nemorosum was recognized as a species distinct from A. minus (H. Duistermaat 1996), with a different and more restricted circumscription than that used by North American workers. Although most of the characters that Duistermaat used to separate those A. nemorosum from A. minus overlap extensively, the consistently wider mid phyllaries of A. nemorosum (1.7–2.5 mm wide versus 0.6–1.6 mm in A. minus) supposedly distinguish the species. None of the North American specimens examined in preparation of this treatment had the wide phyllaries of A. nemorosum in the sense of Duistermaat, who stated that she had seen no material of this taxon from the American continent. Some American authors have taken up the name Arctium vulgare in place of A. nemorosum and applied A. vulgare (dubbed woodland burdock) to the larger-headed North American plants. Duistermaat considers A. vulgare to be a synonym of A. lappa.

Comments: Ontario report (Riley 1989) needs confirmation (Morton & Venn, 1990). Not listed by Kartesz (1994 or 1999). IPNI (searched 9Jan02) accepts this name as published. Ontario CDC accepts as a rare exotic species (1995 data, current May 2002).