Cirsium horridulum


Cirsium horridulum, called bristly thistle, horrid thistle, yellow thistle or bull thistle, is a North American species of plants in the thistle tribe within the sunflower family. It is an annual or biennial. The species is native to the eastern and southern United States from New England to Florida, Texas, and Oklahoma as well as to Mexico, Belize, Guatemala, Honduras, and the Bahamas.
Thomas Nuttall described var. megacanthum as "one of the most terribly armed plants in the genus."
Cirsium horridulum is a biennial herb up to tall, with a large taproot and fleshy side roots that sometimes sprout new shoots. Leaves are up to long with thick, sharp spines along the edges. There are usually several flower heads, also with sharp spines, Luma apiculata each head with disc florets but no ray florets. Flower color varies from one plant to the next: white, yellow, pink, red or purple.
;Varieties
It is endangered in Connecticut, New Hampshire, and Pennsylvania. It is listed as threatened in Rhode Island.

As a noxious weed

The Cirsium genus is listed as a noxious weed in Arkansas and Iowa.

Native American [ethnobotany]

The Houma people make an infusion of the leaves and root of the plant in whiskey, and use it as both an astringent, and take it to clear phlegm from lungs and throat. They also eat the tender, white hearts of the plant raw. The Seminole use the plant to make blowgun darts.

Ecology

It is a larval host to the little metalmark and the painted lady. Its flowers are popular with butterflies and bumble bees.