Touch-Me-Not family (Balsaminaceae)
Description: This plant is a summer annual that becomes 2-5' tall, branching occasionally. The round stems are glabrous and succulent, pale green to pale reddish green, and somewhat translucent. They are rather fragile and break easily. The alternate leaves are up to 5" long and 2½" across, although they are usually about half this size. The leaves are ovate, thin-textured, and hairless. There are low broad teeth along their margins. While the stems are often shiny, the leaves have a dull upper surface. The slender petioles are up to 2" long and usually shorter than the blades of the leaves.
From the axils of the upper leaves, there occurs small clusters of 1-3 orange flowers. These flowers are held horizontally on drooping pedicels. Each flower is about 1" long and has a conical shape with upper and lower lips. There are 3 sepals and 5 petals (although this is difficult to discern). Two lateral sepals are small and membrananous; they are light green to light yellow and are located behind the upper lip. The third sepal forms the conical posterior of the flower, including the small nectar spur. This portion of the flower is typically light orange and shiny; the nectar spur usually bends forward to a position underneath the rest of the flower. The petals form the front of the flower and are usually dark orange with reddish streaks or brown dots. One petal forms the upper lip, which is curved upward, while 2 fused petals form the lower lip. The lower lip often is divided into 2 lobes and functions as a landing pad for visiting insects. There are also 2 smaller lateral petals between the upper and lower lips of the flower. A cluster of stamens with white anthers lies underneath the ovary near the upper lip. The blooming period occurs from mid-summer to early fall, and lasts about 2 months. There is no floral scent. During the fall, insignificant cleistogamous flowers form seed capsules with fertile seeds without any need for cross-pollination. These oblong seed capsules are divided into 5 sections, which split apart, flinging the large seeds a considerable distance. The root system consists of a shallow branching taproot. This plant often forms colonies by reseeding itself.
Cultivation: The preference is light shade to partial sun, wet to moist conditions, and a fertile soil with an abundance of organic material. Submergence of the roots by flood water is tolerated for up to 2 weeks without apparent ill-effects. Sometimes the leaves are affected by mildew late in the year. It is easy to start this plant from seed.
Range & Habitat: The native Orange Jewelweed is a common plant that occurs in most counties of Illinois; it is less common in the NW area of the state. Habitats include openings in moist woodlands, partially or lightly shaded floodplains along rivers, edges of woodland paths, swamps, seeps and fens, and roadside ditches. This species tolerates disturbance better than most wetland plants.
Faunal Associations: The flowers attract the Ruby-Throated Hummingbird and long-tongued bees, including bumblebees and honeybees. Swallowtail butterflies are less common visitors. These visitors seek nectar; many long-tongued bees also collect pollen. Sometimes bumblebees will steal nectar by chewing holes near the spur of the flower. Various smaller insects (e.g., Syrphid flies) will visit the same holes to steal nectar. The caterpillars of several moths feed on the foliage, including Euchlaena obtusaria (Obtuse Euchlaena), Spilosoma latipennis (Pink-Legged Tiger Moth), Trichodezia albovittata (White-Striped Black), and Xanthorhoe lacustrata (Toothed Brown Carpet). Upland gamebirds eat the large seeds, including the Ruffed Grouse, Ring-Necked Pheasant, Greater Prairie Chicken, and Bobwhite Quail. Among mammals, White-Tailed Deer browse on the foliage, while the White-Footed Mouse eats the seeds.
Photographic Location: A partially shaded roadside ditch along a woods near Urbana, Illinois.
Comments: The attractive orange flowers glisten in the sunlight, hence the name 'Jewelweed.' The other Jewelweed in this genus is Impatiens pallida (Yellow Jewelweed). The latter has similar foliage, but its flowers are pale yellow. The Jewelweeds have a muciliginous sap that is supposed to soothe skin irritation caused by Poison Ivy and Stinging Nettle. This sap also has fungicidal properties and has been used to treat Athlete's Foot. The cultivated Impatiens of the horticultural industry have been introduced from such areas as East Africa and New Guinea. They rarely escape from cultivation and are not considered a significant threat to native habitats.