The very large, coarse-looking leaves of burdock (blades sometimes half a meter long) might remind one of rhubarb. Each head is dispersed as a bur covered with hooked spines. Both of our species are Eurasian natives, the commoner one, at least, familiar as a weed of disturbed places.

1. Mature heads ca. 2.5–4.5 cm broad (including spines), all or mostly on pedicels ca. 2.4–16 cm long, in terminal, corymbiform inflorescences; phyllaries smooth (at most weakly glandular) on margins and green (except for brownish spine-tips).

A. lappa

1. Mature heads ca. 1.5–2.8 (–3.5) cm broad, all or mostly on pedicels ca. 0.5–3 (–4) cm long, in elongate racemose or paniculiform inflorescences; phyllaries minutely serrulate below the middle and often purplish toward the apex.

A. minus

All species found in Arctium

Arctium lappaGREAT BURDOCK 
Arctium minusCOMMON BURDOCK 


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. August 21, 2017.