Vernonia lettermannii, known as Letterman's ironweed, is covered with purple flowers in September and October produced by a rounded 4' x 4' herbaceous perennial from the dry stony soils of the Ozark Mountains of Arkansas and Oklahoma. Butterflies and other nectar seeking insects flock to this plant when it comes into flower. Requires well drained soils on the dry side in the Chicago region in order to thrive. Insect and disease resistant.

In an evaluation of ironweeds conducted at the Chicago Botanic Garden, Letterman's ironweed was rated as a good choice for growing in the Chicagoland area in terms of disease resistance and overall performance.