Carolina Thistle, Cirsium carolinianum

Carolina Thistle, Cirsium carolinianum https://warcapps.usgs.gov/PlantID/Species/Details/439, is a biennial or short-lived native perennial that grows to about 4 ft tall. It produces beautiful fluffy purple flowers from April to

July and loves full sun. The common eastern bumble bee and many butterflies

and moths love this flower. Grasshoppers eat the foliage of this plant.

As the flower matures, seeds form and will blow away if you do not put a mesh

bag over the flower as they ripen. The seed germinates easily with no per-

treatment. Thistles are wonderful because they feed many bees and butterflies! If

you are a lover of thistles, you will enjoy this plant. Many of the thistles that show

up in Louisiana are not native and are problematic as invasives.

Canada Thistle, Cirsium arvense, https://plants.ces.ncsu.edu/plants/cirsium-arvense/ is a Tier 2 invasive thistle that is native to Europe, Asia, and Africa and can be found in wet areas. It has deep extending roots that allow it to spread quickly and dominate areas.

Bull Thistle, Cirsium vulgare, https://plants.ces.ncsu.edu/plants/cirsium-vulgare/ is a Tier 2 invasive biannual species that is native to Europe. It has spined leaves and stems and is often found in disturbed areas. This plant can form thickets.

Musk Thistle or Nodding Thistle, Carduus nutans, https://fsus.ncbg.unc.edu/show-taxon-detail.php?taxonid=5833 is a Tier 2 invasivebiannual species that is native to Europe and Asia. It can be difficult to control because it produces thousands of seeds. Invasive thistles were a problem in our pastures when we had grazing animals, so we found it is very important to keep the plant from producing seeds. We watched the plants closely and removed them by mechanical means. Because of their prickly nature and the risk of seeds dispersing, we found it easy to place a bag over the plant and then use a shovel to remove the base of the plant.

Another Beautiful Native Thistle

Bristle Thistle, Cirsium horridulum, https://www.wildflower.org/plants/result.php?id_plant=ciho2 is sometimes called Bull Thistle, which is confusing because we have an invasive with the same common name. It is important to use the scientific name. LSU Ag has a great video on foraging this plant https://www.facebook.com/watch/?v=643349625119593 .

Xerces’s publication, Native Thistles a Conservation Practitioners Guide, https://xerces.org/publications/guidelines/native-thistles-conservation-practitioners-guide is an excellent resource for learning more about thistles. The Carolina Thistle is

available for purchase at the ANPP propagation area on Sunday mornings at the

UL Ecology Center. Check the inventory for availability. (At the bottom of the

inventory spreadsheet, there is a tab for UL Ecology). -Louise Prejean