Circaea lutetiana canadensis
Evening Primrose family (Onagraceae)
Description: This perennial plant is about ¾-2' tall and unbranched or little branched. Scattered white hairs occur occasionally along the central stem, although it becomes glabrous with age. The opposite leaves are up to 5" long and 3" across (excluding the petioles); they are ovate-cordate, dentate along their margins, and largely hairless. The upper leaf surface is medium to dark green and hairless. The slender petioles of the leaves are up to 1½" long and medium green. The central stem terminates in a raceme of flowers up to 6" long. The stalk of this raceme has scattered white hairs. The small flowers are sparsely, but evenly, distributed along this stalk on slender pedicels up to ½" long. These pedicels spread outward.
Each flower consists of 2 white petals, 2 green sepals, 2 stamens, and a slender style. Each petal is deeply divided into 2 lobes. At the base of each flower, there is a 2-celled ovary that is green and covered with stiff hooked hairs; it is obovoid in shape. Each cell of this ovary contains a single seed. The blooming period for a colony of plants occurs during the summer and lasts about a month. Each flower is short-lived and replaced by a small bur-like fruit (see the description of the ovary above). The root system can produce rhizomes or stolons that extend through the soil or leaf mould to create clonal offsets from the mother plant.
Cultivation: The preference is dappled sunlight to medium shade, more or less mesic conditions, and a rich loamy soil with abundant organic matter.
Range & Habitat: The native Enchanter's Nightshade is an occasional to locally common plant that occurs in most counties of Illinois (see Distribution Map). This plant may be less abundant than in the past because of browsing by deer. Habitats include mesic deciduous woodlands, including oak woodlands and maple/basswood woodlands, and areas that are adjacent to woodland paths. Sometimes this species occurs in wooded upland areas and along ravine slopes.
Faunal Associations: The nectar and pollen of the flowers attract small bees, including Halictid bees (Lasioglossum spp.) and little carpenter bees (Ceratina spp.); they are also visited by Syrphid flies and bee flies (Bombyliidae). The caterpillars of a moth, Mompha terminella (Enchanter's Cosmet), are blotch leaf-miners. Birds and mammals help to distribute the seeds, as the small bur-like fruits can cling to feathers and fur; these fruits can cling to the clothing of humans as well. Deer occasionally browse on the foliage of Enchanter's Nightshade.
Photographic Location: A mesic deciduous woodlands at Busey Woods in Urbana, Illinois.
Comments: This is one of the woodland wildflowers that blooms during the summer in shaded areas. The flowers of such species are usually small, white, and not very showy. Enchanter's Nightshade is a rather odd member of the Evening Primrose family, as its flowers have only 2 petals, 2 sepals, and 2 stamens. This is a distinctive characteristic of the Circaea genus in this family. The only other member of this genus that occurs in Illinois, Circaea alpina (Small Enchanter's Nightshade), is an uncommon species that is restricted to the cool moist woodlands of northern Illinois. It has leaves that are more cordate and indented at the base, and its flowers are clustered toward the apex of the flowering stalk (rather than being evenly distributed along this stalk). While Enchanter's Nightshade is ¾-2' tall and it has 2-celled ovaries, Small Enchanter's Nightshade is less than 1' tall and it has 1-celled ovaries.