Impatiens capensis

Even though Impatiens capensis has been given several names by different authors at the specific level, and flower color and height can vary, there is apparently little disagreement on what constitutes this species, and no subspecies or varieties are recognized (Gleason and Cronquist 1963, Kartesz 1999, Swink and Wilhelm 1994).

Impatiens capensis is very common and demonstrably secure in many parts of its range, although it is probably somewhat imperiled locally in other areas. Human activities are likely impacting this species through the destruction, fragmentation, and degradation of its wetland habitats, but at this time these activities have not caused a significant decline. Wild harvesting of this species for medicinal use is limited, local, and unlikely to be a financially lucrative enterprise in the near future.

Impatiens capensis occurs from Alaska southwards through most of the Canadian provinces and into the eastern two-thirds of the continental U.S. Populations occur as far west as Colorado, with an additional disjunct grouping of populations in Oregon, Washington, and Idaho (USDA-NRCS 1999). Hulten (1968) reports that I. capensis is also described from Europe, but corroborating sources are not known. It is reported from 17 counties in Mississippi, becoming uncommon to rare in the southern one third of the state (Mississippi Natural Heritage Program). It is reported from almost every county in Arkansas (Arkansas Natural Heritage Commission). It is common throughout Michigan (Michigan Natural Features Inventory). It is restricted to the eastern quarter of the state of Kansas (Kansas Natural Features Inventory). It is adventive in Boulder County, Colorado (Weber and Wittmann 1992). It occurs in the southern half of Manitoba (Manitoba Conservation Data Centre).

Tens of thousands of populations are likely extant rangewide. British Columbia: >30; Manitoba: >100; Mississippi: numerous, from 17 counties primarily in the northern part of the state; Michigan: numerous and common; Ontario: very common, many thousands; Georgia: ubiquitous in the northern half of the state; very common in Kentucky, Indiana, Illinois, Nebraska, Delaware, Missouri, and New York; New Hampshire: not rare; Kansas: 150-200, restricted to the eastern quarter; Texas: rare, easternmost part of the state barely makes it into the range of this species.

Any assessment of the wild population collection threat to I. capensis would need to consider the fact that it is annual, and essentially survives from year to year by successful seed production. Because the fresh juice must be used to obtain the medicinal benefits of this plant, its commercial value in the wild plant trade may be somewhat limited (Kara Dinda pers. comm.). It is listed as an "herb that can be commonly gathered" (Frontier Co-op 2000).

It is reported that this species would be difficult to cultivate for several reasons. It requires 75% shade as does ginseng. It must be grown from seed due to its annual life history and shallow, poorly developed root system. The seeds are difficult to collect because the fruits shatter immediately upon ripening. The seeds may also require cold treatment to germinate (Kara Dinda pers. comm.).

An individual familiar with the herbal medicinal trade in the U.S. states that this species receives little commercial attention, and that use is primarily on a local basis (McGuffin pers. comm.).

This species is collected on a very small scale in Mississippi, where such harvesting has little impact on the species (Ronald Wieland pers. comm.). The vast majority of all plant material used is wildcrafted (Ed Fletcher pers. comm.).

In Manitoba, there is no evidence to suggest that it is being collected. Native people may possibly collect it (Manitoba Conservation Data Centre).

The loss of wetlands in North America constitutes a great threat to the habitat of I. capensis. However, I. capensis occurs in a wide range of community types, and can appear in disturbed areas, which both suggest that I. capensis has reasonable prospects for survival on an ecologically damaged landscape (Swink and Wilhelm 1994, Weber and Wittmann 1996b). In Mississippi, the bottomlands in which this species is found are not disturbed to the extent that the surrounding uplands are. Though some wetlands are being converted, this poses little threat to this species in Mississippi at this time (Ronald Wieland pers. comm.). Threats include fragmentation and degradation of wetlands in Michigan, but this species is demonstrably secure (Mike Penskar pers. comm.). In Manitoba, threats include wetland and land drainage, road maintenance activities, forestry practices, and land clearing (Manitoba Conservation Data Centre).

Because each plant yields very little juice and does not dry well for preservation, wild populations could be devastated rather quickly if the species were to become popular as an herbal remedy (Kara Dinda pers. comm.).