College Green Magazine – Eco-news From The Ground Up

A bee enjoying the bloom of the common teasel along Stroud’s Run. Photo by Emma Dean, CG Science Editor

By Emma Dean, CG Science Editor

The common teasel is an invasive species that came to North America from Europe in the 1700’s.  Today, this plant is found along the Pacific Coast, northeastern United States and southern Canada.  Although it is often considered a weed that is dangerous because of its aggressive tendency to create a monoculture and outcompete native species, the common teasel is used in horticultural plantings and also in dried floral arrangements.

The typical habitats of the common teasel in Ohio include pastures, fields, roadsides, railroads and waster areas as the plant maintains a preference for damp, fertile soils.  Between July and September, the common teasel will bloom purple flowers.  Its relative, the cut-leaved teasel blooms white flowers.

One single teasel can produced over 2,000 seeds.  Of those thousands of seeds, between 30 to 80 percent will successfully germinate, plus seeds remain viable for at least two years.  However, for the extensive amount of seeds produced, most travel only about five feet from the mother plant.  Birds such as goldfinches and blackbirds have been known to feed on the seeds so it is assumed that dispersal is aided through birds as well as via water.  Over the past 30 years, the common teasel population has exploded with highway mowing being cited as a possible cause.

Several common teasels post-bloom found along Stroud’s Run. Photo by Emma Dean, CG Science Editor

Fast Facts:

• The common teasel has a large taproot up to two feet in length with a diameter of about one inch at the crown in addition to fibrous secondary roots.
• Flowering stems grow to be a towering six to seven feet in height.
• For those who find the plant to be a nuisance, nonchemical recommendations for removal and control include cutting, digging and burning.
• Other names for the common teasel are barber’s brush, brushes and combs, card teasel, card-thistle, church broom, gypsy-combs, Venus’ basin, Venus’-cup and wild teasel.
• Dipsacus is a word derived from the Greek verb meaning “to be thirsty” which is most likely a reference to the way the leaves fuse around the flowering stem and form a cup that collects rainwater.

Sources:

Common Teasel

Ohio Perennial and Biennial Weed Guide