Field Thistle

Common Name: Field Thistle.

Scientific Name: Cirsium Discolor.

What to look for?  Weedy-looking plant with lovely pink tubular flowers atop a spikey globe. The Field Thistle has moderate height with lateral branches from its main stem that remain erect. The stems are light green with noticeable white hairs. The leaves are long and quite spiny. They are green on the upper surface, but powdery white on the lower surface because of minute fine hairs. Flowerheads are pink and consist of numerous disk florets. At the base of each flowerhead, there are overlapping floral bracts or phyllaries that are light green with white central veins – spiky-looking. Each floral bract has a single slender spine. The achenes or seeds develop with tufts of white hair, which facilitates their dispersal by wind. The root system consists of a central taproot and some coarse secondary roots. However, vegetative spread by rhizomes does not occur.

Where can they be found at Carillon Stonegate Pond? Field Thistle pop up in the meadow areas around Carillon Stonegate Pond and around the fields near Arlene Shoemaker forest preserve.

How big are they? Field Thistle grows from two (2) feet up to six (6) or more feet tall. The large, basal leaves are approximately nine (9) inches long and three (3) inches across. Each flower head is approximately one (1) to two (2) inches across.

Where do they grow and thrive? The native Field Thistle occurs across most areas of Illinois. Across the U.S., this plant is found in most states from the Great Plains (except Oklahoma) east. Field Thistle is found in prairies, openings in woodland areas, moist meadows, limestone glades, pastures and abandoned fields, and open areas along railroads and roadsides. This plant is more abundant in disturbed areas.

When do they bloom? The blooming period of the Field Thistle is from late summer to fall, lasting about a month.

Do birds, insects or other wildlife associate with this plant? The most important pollinators of the flowers of the Field Thistle are bumblebees, several other bees, and butterflies. Among the butterflies, are Monarchs, Painted Ladies, Swallowtails, and Sulfurs. The Ruby-Throated Hummingbird sometimes visits the flowers for nectar. Other animals avoid this plant because of the spines.

Interesting Facts About the Field Thistle:

  • There are 58 species of Cirsium thistles native to North America.

  • The genus Cirsium is from the Greek word kirsion - for a particular thistle and has been adopted for a number of plants generally not appreciated by gardeners.

  • The species discolor means 'of two different colors' (usually distinct colors), referring to the upper and underside leaf color of this species.

  • Flowers do not have a fragrance.

  • During the month of August, when other forbs are less likely to flower, this plant produces some patches of pink color, making the prairie more interesting during this time of year.

For more information on the Field Thistle and sources of information used in this blog (these are several of the sources that I am using to learn as I blog), please visit Illinois Wildflowers, Minnesota Wildflowers, and Friends of the Wildflower Garden.

The Carillon at Stonegate community is very fortunate to have a variety of wetland, forest and prairie environments conducive to a variety of birds and other wildlife, insects and plants. Our community and the Kane County Forest Preserve do an exceptional job in maintaining this natural environment – both for the benefit of the birds and wildlife and for our residents to enjoy.

 

Take a hike and see what you can find – and identify!