Impatiens capensis

Orange jewelweed
File:Potapsco fg13.jpg
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Ericales
Family:	Balsaminaceae
Genus:	Impatiens
Species:	I. capensis
Binomial name
Impatiens capensis Meerb.
Synonyms
Impatiens biflora Walter Impatiens fulva Nutt.

Impatiens capensis, the orange jewelweed, common jewelweed, spotted jewelweed, spotted touch-me-not, or orange balsam, is an annual plant 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).

File:Orange Jewelweed, Ottawa.jpg

Flowers and leaves

The flowers are orange 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. The stems are somewhat translucent, succulent, and have swollen or darkened nodes. The seed pods are pendant and have projectile seeds that explode out of the pods when they are lightly touched, if ripe, which is where the name 'touch-me-not' comes from. The leaves appear to be silver or 'jeweled' when held underwater, which is possibly where the jewelweed name comes from. Along with other species of jewelweed it is a traditional remedy for skin rashes, although controlled studies have not shown efficacy for this purpose.

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.

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.

Pollination

Nectar spurs are tubular elongations of petals and sepals of certain flowers that usually contain nectar. Flowers of Impatiens capensis have these nectar spurs. Nectar spurs are thought to have played a role in plant-pollinator coevolution. Curvature angles of nectar spurs of Impatiens capensis are variable. This angle varies from 0 degrees to 270 degrees.

The angle of the nectar spur is very important in the pollination of the flower and in determining the most efficient pollinator. Hummingbirds are the main pollinators. They remove more pollen per visit from flowers with curved nectar spurs than with perpendicular nectar spurs. But hummingbirds are not the only pollinators of Impatiens capensis. Bees play an important role in pollination as well. Due to hummingbirds and bees, the pollination of Impatiens capensis is very high.

Gallery

• Jewel Weed Impatiens capensis Leaves and Flower 2600px.jpg

  Leaves & flowers

• Jewel Weed Impatiens capensis Creek Side 3200px.jpg

  Jewelweed growing on a creek side

• Potapsco fg13.jpg

  Flower

External links

• USDA Plants Database: Impatiens capensis