Spotted jewelweed

Description

Impatiens capensis, the orange jewelweed, common jewelweed, spotted jewelweed, jewelweed, or orange balsam, is an annual plant which is native to North America. It is common in bottomland soils, ditches, and along creeks, often growing side by side with its less common relative, yellow jewelweed (I. pallida). Jewelweed is an herbaceous plant that grows 3 to 5 feet tall and blooms from late spring to early fall. The flowers are orange (sometimes blood orange or rarely yellow) with a three-lobed corolla; one of the calyx lobes is colored similarly to the corolla and forms a hooked conical spur at the back of the flower. Plants may also produce non-showy cleistogamous flowers, which do not require cross-pollination. It often branches extensively. The round stems are glabrous (smooth) and succulent, and semi-translucent, with swollen or darkened nodes on some plants. The leaves are alternate and simple and have teeth on the margins. The seed pods have five valves which coil back rapidly to eject the seeds in a process called explosive dehiscence or ballistochory. This reaction is where the name 'touch-me-not' comes from; in mature seed pods, dehiscence can easily be triggered with a light touch. Impatiens capensis was transported in the 19th and 20th centuries to England, France, the Netherlands, Poland, Sweden, Finland, and potentially other areas of northern and central Europe. These naturalized populations persist in the absence of any common cultivation by people. This jewelweed species is quite similar to Impatiens noli-tangere, an Impatiens species native to Europe and Asia, as well as the other North American Impatiens. No evidence exists of natural hybrids, although the habitats occupied by the two species are very similar. In the State of Washington, Impatiens capensis is considered a class C noxious weed due to its rapid spread and tendency to outcompete native jewelweeds. It has also formed a hybrid species with the native jewelweed Impatiens ecornuta. The leaves appear to be silver or 'jeweled' when held underwater, which is possibly where the jewelweed name comes from. Another possible source of the name is the color and shape of the bright robin's egg-blue kernels of the green projectile seeds. The species name capensis, meaning "of the cape", is actually a misnomer, as Nicolaas Meerburgh was under the mistaken impression that it was native to the Cape of Good Hope, in southern Africa.