Description: This native perennial plant is about 3-4' tall and unbranched, except near the inflorescence. The stout central stem is hairless, and often has red and green stripes running along its length. The alternate leaves are up to 8" long and 4" across, becoming smaller and fewer as they ascend the central stem. Their texture is thick and rubbery. These leaves are hairless and broadly ovate. Their margins are smooth or have widely spaced blunt teeth; they are often whitish or reddish in appearance.
At the apex of the plant, the
inflorescence branches into several flattened clusters of greenish white
flowerheads, each cluster spanning 2-6" across. Each flowerhead within a
cluster looks like an unopened bud – however, closer inspection reveals 5
white flowers surrounded by 5 green bracts with white stripes. The corolla of
each tiny flower is divided into 5 lobes. There is no noticeable scent to these
flowers. The blooming period lasts about a month and occurs from early to
mid-summer. The root system is tuberous and coarsely fibrous.
Cultivation: The preference is full or partial sun
and moist conditions. This plant can withstand standing water, but not severe
drought. The soil should be rich in organic material, and either a high or low
pH is tolerated. Foliar disease doesn't appear to be
troublesome.
Range & Habitat:
This uncommon plant occurs primarily in NE Illinois, and scattered counties
elsewhere (see
Distribution
Map). At one time, large populations of Prairie Indian Plantain occurred in
wetland areas, particularly in the Chicago region, but they have been largely
destroyed by modern development. This plant still occurs in such habitats as
moist to mesic black soil prairies, dolomite prairies, savannas, thickets,
moist meadows near rivers,
limestone glades, marshes, fens, remnant bogs, and
calcareous seeps. In developed areas, it may occur along ditches near railroads
and roadsides. This is an indicator plant of high quality
habitat.
Faunal Associations: The
flowers appear to attract only a few insect visitors. Those that have been
observed include Sphecodes dichroa (Parasitic Halictid Bee sp.),
Myzinum quinquecincta (Five-Banded Tiphiid Wasp), Lycaena hyllus
(Bronze Copper butterfly), Cisseps fulvicollis (Yellow-Collared Scape
Moth), and Lygaeus turcicus (Lygaeid Bug sp.). These insects were
seeking nectar. There is little or no information available about this plant's
relationship to birds and mammalian herbivores. Because the foliage is neither
toxic nor particularly coarse, it seems likely that mammalian herbiovores feed
on it occasionally.
Photographic
Location: The photographs were taken at Loda Cemetery Prairie in
Iroquois County, Illinois.
Comments:
While the flowerheads are not particularly showy, the thick rubbery leaves
provide this plant with a presence that is quite interesting and different.
This is the only member of the genus Arnoglossum with plantain-shaped
lower leaves. The other members of the genus have lower leaves that are wider
and more angular, which is probably an accomodation to the lower light levels
of the woodland habitats in which they are more likely to occur. While this is
often thought to be a wetland species, it also occurs in mesic black soil
prairies.