''Impatiens capensis'', the orange jewelweed, common jewelweed, spotted jewelweed, jewelweed, spotted touch-me-not, or orange balsam,
is an
annual plant
An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. The length of growing seasons and period in which they take place vary according to geographical ...
in the family
Balsaminaceae
The Balsaminaceae (commonly known as the balsam family) are a family of dicotyledonous plants, comprising two genera: '' Impatiens'', which consists of over 1000 species, and ''Hydrocera'', consisting of 1 species. The flowering plants may be an ...
that is native to
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
. It is common in bottomland soils, ditches, and along creeks, often growing side by side with its less common relative,
yellow jewelweed
Yellow is the color between green and orange on the spectrum of light. It is evoked by light with a dominant wavelength of roughly 575585 nm. It is a primary color in subtractive color systems, used in painting or color printing. In the R ...
(''I. pallida'').
Description
Jewelweed is an
herbaceous
Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials.
Definitions of "herb" and "herbaceous"
The fourth edition of t ...
plant that grows 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
Cleistogamy is a type of automatic self-pollination of certain plants that can propagate by using non-opening, self-pollinating flowers. Especially well known in peanuts, peas, and pansies, this behavior is most widespread in the grass family. How ...
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, which measure up to long and across, are alternate on the upper stems and opposite on the lower stems (when present). The leaves are
ovate
Ovate may refer to:
* Ovate (egg-shaped) leaves, tepals, or other botanical parts
*Ovate, a type of prehistoric stone hand axe
*Ovates, one of three ranks of membership in the Welsh Gorsedd
*Vates
In modern English, the nouns vates () and ova ...
to elliptic, simple, and have shallow, rounded teeth on the margins.
The seed pods have five valves which coil back rapidly to eject the seeds in a process called
explosive dehiscence
Dehiscence is the splitting of a mature plant structure along a built-in line of weakness to release its contents. This is common among fruits, anthers and sporangia. Sometimes this involves the complete detachment of a part; structures that op ...
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.
Distribution
''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
Washington (), officially the State of Washington, is a state in the Pacific Northwest region of the Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the Washington ...
, ''Impatiens capensis'' is considered a class C
noxious weed
A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is injurious to agricultural or horticultural crops, natural habitats or ecosystems, or humans or liv ...
due to its rapid spread and tendency to outcompete native jewelweeds. It has also formed a hybrid species with the native jewelweed ''
Impatiens ecornuta
''Impatiens ecornuta'', the spurless touch-me-not or western touch-me-not, is an annual flowering plant native to the northwestern United States and British Columbia in Canada. ''.
Uses
As food
The young shoots can be boiled (with two changes of water) as a
potherb
Leaf vegetables, also called leafy greens, pot herbs, vegetable greens, or simply greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots. Leaf vegetables eaten raw in a salad can be called salad gre ...
; eating too much is not recommended as the plant contains
calcium oxalate
Calcium oxalate (in archaic terminology, oxalate of lime) is a calcium salt of oxalic acid with the chemical formula . It forms hydrates , where ''n'' varies from 1 to 3. Anhydrous and all hydrated forms are colorless or white. The monohydrate ...
crystals.
The seeds are also edible.
Medicinal
Along with other species of
jewelweed
''Impatiens'' is a genus of more than 1,000 species of flowering plants, widely distributed throughout the Northern Hemisphere and the tropics. Together with the genus ''Hydrocera'' (one species), ''Impatiens'' make up the family Balsaminaceae. ...
, the juice of the leaves and stems is a traditional Native American remedy for skin rashes, including
poison ivy. The effectiveness of its use to prevent the development of a rash after short-term exposure to poison ivy has been supported by peer-reviewed study, and is likely due to the plant containing
saponin
Saponins (Latin "sapon", soap + "-in", one of), also selectively referred to as triterpene glycosides, are bitter-tasting usually toxic plant-derived organic chemicals that have a foamy quality when agitated in water. They are widely distributed ...
s. These studies also found that some individuals have a sensitivity to jewelweed which can cause a more severe rash.
The stem juice has also been used to treat
athlete's foot
Athlete's foot, known medically as ''tinea pedis'', is a common skin infection of the feet caused by a fungus. Signs and symptoms often include itching, scaling, cracking and redness. In rare cases the skin may blister. Athlete's foot fungus m ...
; its
fungicidal
Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, ...
qualities have been scientifically verified.
Etymology
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. Both the genus name ''Impatiens'' ("impatience" in Latin) and common name spotted touch-me-not refer to how its seeds when ripe pop open on touch.
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
The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa.
A common misconception is that the Cape of Good Hope is t ...
, in southern
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
.
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
Hummingbirds are birds native to the Americas and comprise the biological family Trochilidae. With about 361 species and 113 genera, they occur from Alaska to Tierra del Fuego, but the vast majority of the species are found in the tropics aro ...
are major 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
Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamil ...
, especially
bumblebee
A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related gener ...
s play an important role in pollination as well. Due to hummingbirds and bees, the pollination of ''Impatiens capensis'' is very high.
Gallery
File:Jewel Weed Impatiens capensis Leaves and Flower 2600px.jpg, Leaves and flowers
File:Jewel Weed Impatiens capensis Creek Side 3200px.jpg, Jewelweed growing on a creek side
File:Potapsco fg13.jpg, Flower
File:2017-09-02 16 32 48 Jewelweed in flower just after rain with water beading on the leaves (hence the name 'Jewelweed') along a walking path in the Franklin Farm section of Oak Hill, Fairfax County, Virginia.jpg, Leaf showing beads (jewels) just after rain
References
External links
Jewelweed
{{Taxonbar, from=Q2462343
capensis
Flora of North America
Plants described in 1775
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