Ear-Leaved False Foxglove
Snapdragon family (Scrophulariaceae)
Description: This native annual plant is about ½–2½' tall and unbranched. The central stem is round and has numerous white hairs. The opposite leaves are about 2" long and ¾" across. They are broadly lanceolate and sessile against the stem, with smooth margins and fine white hairs covering the upper and lower surfaces. Each of the upper leaves usually have two small lobes at the base, which resemble ears. The inflorescence consists of a spike of flowers in the upper half of the plant. These flowers are purple, pinkish purple, or lavender. Each tubular flower is about ¾" long, with 5 short lobes that flare outward. Sometimes there are purple dots inside the corolla. The reproductive parts consist of 4 stamens and 1 stigma near the upper inner surface of the corolla. Each flower is subtended by a large green calyx that is hairy and divided into 5 triangular parts. The blooming period occurs during late summer and lasts about 3 weeks. A fruit develops within each calyx that contains numerous small seeds. At this time, the entire plant becomes reddish brown. These seeds are probably distributed by the wind to some extent. The root system consists of a central taproot and secondary roots – the latter are often parasitic on the roots of other plants, particularly Aster spp. However, in the absence of a suitable host, Ear-Leaved False Foxglove can meet its own needs adequately through photosynthesis.
Cultivation: The preference is full or partial sun and mesic conditions. This plant typically grows in rich, loamy soil. It appears to have few problems with disease. The seeds can be slow to germinate; it is possible that a heat treatment simulating the effects of a wildfire may be beneficial in this regard.
Range & Habitat: Ear-Leaved False Foxglove is a rare plant that occurs in scattered counties throughout most of Illinois, except the extreme south (see Distribution Map). It is state-listed as a threatened plant. Habitats include mesic black soil prairies, thickets containing grasses and occasional shrubs, savannas, woodland borders, abandoned fields, and areas along railroads (particularly where remnant prairies occur). This plant is found in both high quality habitats and somewhat disturbed areas. It is intolerant of frequent mowing or grazing; however an occasional wildfire may improve germination of the seeds, as well as reducing competition from shrubs and other kinds of plants. The species Aster ericoides (Heath Aster) and other aster species of mesic black soil prairies are beneficial because they are suitable hosts for the parasitic roots.
Faunal Associations: Bumblebees are the most important pollinators of the flowers, where they seek nectar. Other long-tongued bees also visit the flowers, including miner bees and leaf-cutting bees. Little information is available about this plant's relationship to mammalian herbivores; because the foliage is not known to be toxic, it is probably consumed by them occasionally.
Photographic Location: The photograph of the plant in flower was taken by Lisa Culp (Copyright © 2009) at a nature preserve in Cook County, Illinois, while the lower photograph was taken by the webmaster at a prairie remnant along a railroad in Iroquois County, Illinois.
Comments: This wildflower is easy to identify because of the small basal lobes on some of its leaves. It is closely related to the purple-flowered Agalinis spp., which are also partially parasitic on other plants. In addition to its peculiar basal lobes, Ear-Leaved False Foxglove has wider leaves than the latter species.