Mystery of the Month: August

Photo (Art!) by Paul Erdmann.

  
Guess who sponsored a state-wide graphic design/botony competition for high-school students to see who could invent the coolest and most believable Flower From Mars.

The answer? We don't know, but it sounds like a great idea. 

Perhaps the students would have come up with something like the image here, but this is not instagram or art class, folks. This sky-scraping bloom is real. What is it?

Meet a couple cousins in the Dipsacus family.


Cut-leaf teasel (Dipsacus laciniatus L. with white flowers) and common teasel (Dipsacus fullonum L. with purple or pink flowers) came to the U.S. from Europe. Prickly dried teasel flower-heads were once used in the fabric industry for wool carding and fabric-knapping. More recently used in dried flower arrangements, they escape areas near cemeteries and spread along roadsides, grasslands and waterways. First year plants stay low to the ground, in a dandelion-like rosette form. The rosette grows bigger each year, reaching an incredible 2-foot diameter. Flowering stalks are formed once rosettes reach a critical mass. The plant dies at the end of the flowering year.  

 

Teasel grows up to seven feet tall, with opposite leaves which join around the stem, forming a water-holding “cup”, serving as mosquito nurseries. The entire plant is extremely prickly! Plants typically branch and produce multiple flower heads, blooming in July and early August. Flowers on the large cylindrical heads bloom in successive rings instead of all at once. One plant may generate three thousand seeds. Teasel seeds stick to mowers, feet and tires and can float in water, contributing to its spread. Goldfinches, mice and other animals eat the seeds, possibly bringing it to new areas.


Both species of teasel are listed as prohibited/eradicate species on the Minnesota Noxious Weed List. Eradication is required by Minnesota Statutes. It is illegal to propagate, sell or transport this plant. 
 


How can you help prevent the spread of teasel?

An infestation of cut-leaf teasel in Roseville, MN was likely begun by someone tossing a dried arrangement into a vacant lot. Please dispose of all potted plants, arrangements and wreaths of any species in a responsible manner. Do not plant teasel or buy dried flower arrangements containing teasel. Report teasel found in Ramsey County to the Ramsey County Cooperative Weed Management Area; carole.gernes[@]rwmwd.org. In other areas of Minnesota, call the Arrest the Pest hotline: 888-545-6684.