Plantain family (Plantaginaceae)
Description: This herbaceous perennial plant is consists of a low rosette of basal leaves about 5-12" across, from which one or more flowering stalks develop. The blades of the basal leaves are 2-5" long and 1½–3" across; they are oval in shape with about 5 parallel veins and smooth margins. The upper surface of each blade is medium green and glabrous to sparsely canescent, while the lower surface of each blade is light green and sometimes finely pubescent along the veins. The petioles are a little shorter than their blades, light green, and usually glabrous. The upper surface of each petiole has a concave groove along its length. The flowering stalks are 4-20" long, unbranched, and more or less erect. The lower one-third of each stalk is green, terete, glabrous to finely pubescent, and naked; a narrowly cylindrical spike of greenish flowers occurs along the upper two-thirds of each stalk. These small flowers are densely distributed along the spike. Each flower is only 1/8" (3 mm.) long, consisting of 4 green sepals, a pistil with a single white style, 4 stamens with pale purple anthers, and a papery corolla with 4 spreading lobes. Each sepal has a green keel and membranous margins; it is ovate to oval in shape (including the margins). The tiny lobes of the corolla are lanceolate in shape and smaller than the sepals. At the base of each flower, there is a green bract that is ovate to oval in shape and about the same length as the sepals. The blooming period can occur from early summer to early fall. A single floral spike remains in bloom for about 2 weeks, but the same plant can produce a succession of spikes that bloom at different times of the year. Furthermore, some plants produce their spikes earlier or later than others. The flowers are wind-pollinated. The flowers are replaced by ovoid seed capsules that are individually about 3 mm. long at maturity; they are initially green, but later become purple or brown. Each seed capsule is circumsessile and splits open around the middle to release the seeds. Each capsule contains about 6-15 seeds. The seeds are 1.0–1.5 mm. long, light to dark brown, and somewhat flattened; the seed surface is finely reticulated (requires 10x hand lens to see). The root system consists of a short crown with fibrous roots.
Cultivation: Common Plantain prefers full or partial sun, moist to mesic conditions, and soil containing loam or clay loam. It tolerates considerable compaction of the soil, but the size of individual plants will be somewhat smaller. Individual seeds can remain viable for up to 60 years and require light to germinate.
Range & Habitat: Common Plantain is common in NE Illinois, occasional to locally common in central Illinois, and occasional to absent elsewhere in the state (see Distribution Map). It is likely that this plant is more widely distributed than official records indicate. Common Plantain was introduced from Europe and it is widely distributed across the continent of North America. Habitats include lawns, mowed roadsides, compacted soil along paths, vacant lots, and waste areas. Areas with a history of human-related disturbance are preferred. This plant is more common in urban and residential areas than elsewhere.
Faunal Associations: Because the flowers are wind-pollinated, they attract few insect visitors. However, Syrphid flies sometimes feed on the pollen. The caterpillars of the butterfly Junonia coenia (Buckeye) and several species of moth (see Moth Table) feed on Plantago spp. (primarily the foliage). Other insect feeders include Dysaphis plantaginea (Rosy Apple Aphid), Dibolia borealis (Flea Beetle sp.), Gymnaetron pascuorum (Seedpod Weevil sp.), and Melanoplus bivittatus (Two-Striped Grasshopper). Cardinals, Grasshopper Sparrows, and probably other birds feed on either the seeds or seed capsules to a minor extent; the Ruffed Grouse occasionally eats the leaves. The leaves and flowering stalks of Common Plantain are readily consumed by groundhogs, rabbits, deer, cattle, sheep, and other mammalian herbivores.
Photographic Location: A lawn on the campus of the University of Illinois in Urbana, Illinois.
Comments: This is a common lawn weed that is able to resist mowing because of its low basal leaves. Even stunted specimens of this plant can produce small flowering spikes. Common Plantain is very similar in appearance to the native Plantago rugelii (Black-Seeded Plantain), which is another common lawn weed. The easiest way to distinguish these two species involves an examination of the seed capsules on a a mature floral spike (one that has become purple or brown). Common Plantain has ovoid seed capsules that split open around the middle at maturity. In contrast, Black-Seeded Plantain has oblongoid seed capsules that split open toward the bottom at maturity. By applying pressure with the fingers, it is possible to split open the seed capsules a little prematurely. These two species also differ in the appearance of their seeds and the shape of their sepals.