Plant Profile: Arctium minus

Common Burdock is a biennial wildflower from the Aster family, often regarded as a weed. Originally from Europe, it has spread extensively across various regions worldwide. Accidentally introduced to the United States, this resilient plant aggressively colonizes disturbed environments such as vacant lots, parks, roadsides, prairies, fields, and pastures. It is listed by the USDA as an introduced, invasive, and noxious species, prevalent throughout much of North America. While some states classify it as invasive, North Carolina has not yet done so. Once it takes root, Common Burdock is notoriously difficult to eliminate due to its deep taproots and the vast number of seeds it produces, which can remain viable for extended periods even after the plant is removed. A single plant can generate up to 15,000 seeds, allowing it to outcompete beneficial native flora.

In its first year, Common Burdock develops a compact rosette of leaves. By its second year, it can grow to heights of 3 to 6 feet, featuring large, heart-shaped leaves and clusters of pink to purple thistle-like flowers on branched stems. The slender taproots can reach depths of up to one foot. The flowerheads, which are found at the top of the stems, consist of numerous disk florets surrounded by globular bracts that end in fine, sharp hooks, forming prickly burs. These burs facilitate seed dispersal by attaching to animals, birds, or hay bales, and they are notoriously difficult to remove. There have been reports of small birds and bats becoming entangled in these burs, leading to fatalities. The fruits, or achenes, within the burs contain tiny bristles (pappus hairs) that can easily become airborne, posing risks of severe irritation or infection to the eyes, skin, and respiratory systems of humans and animals alike, including dogs, horses, and livestock. In dairy animals, significant consumption of Common Burdock can taint milk. Bumblebees, honeybees, miner bees, and leaf-cutting bees collect pollen from its flowers and enjoy its nectar, while the foliage serves as a food source for the caterpillars of the Painted Lady butterfly. This plant thrives in full sun and prefers moist, well-drained soil rich in organic matter and nitrogen. However, it can also be susceptible to root rot and powdery mildew, which may adversely affect agricultural crops.

In various parts of Asia and beyond, Common Burdock is cultivated for its edible roots and stems, as well as for medicinal purposes. Cultivated varieties are typically sown from seed in the summer, with the first-year roots harvested by late autumn before they become too fibrous. The young stems can be peeled to reveal a pith that is edible as a vegetable.

**Insects, Diseases, and Other Plant Problems:** This plant is invasive and challenging to eradicate once established. It is prone to powdery mildew and root rot, which can negatively impact agricultural crops. The burs and bristles can cause serious eye, skin, or respiratory issues in humans, dogs, horses, and other livestock, and they are notoriously difficult to remove from animals and clothing.