- Impatiens nevskii
- Small Balsam
- Small-flowered Jewelweed
- Small Yellow Balsam
General: Smallflower Touch-Me-Not is a frost-intolerant succulent annual.
Flowers: Are pale yellow and occur in the leaf axils. They have a straight spur that points backwards.
Stems: Are erect to ascending, smooth, succulent and often branched. Smallflower Touch-Me-Not grows up to 20 – 80 cm tall.
Leaves: Are alternate along the stem, stalked, egg-shaped to elliptic, finely and sharply saw-toothed. They are generally 3 – 12 cm long.
Seeds: Smallflower Touch-Me-Not produces 10 – 20 mm-long capsules that contain many seeds and explode when touched.
Roots: Are shallow and fibrous.
Jewelweed (Impatiens capensis) can be found throughout the Sea to Sky. Unlike Smallflower Touch-Me-Not, its flowers are orange and spotted.
Himalayan Balsam (Impatiens glandulifera) is another invasive species that can be found throughout the Sea to Sky. Compared to Smallflower Touch-Me-Not, the plant is taller and has pink flowers.
Habitat and Origin
Smallflower Touch-Me-Not is native to central Asia. Like other impatiens, it was likely brought over to North America as a garden ornamental.
Smallflower Touch-Me-Not does well in partial to full shade and will grow in moist to damp areas. Nonetheless, it can also withstand drier conditions. It is generally found along river edges, wetlands, lakeshores, forest edges or clearings.
Propagation & Vectors of Spread
Smallflower Touch-Me-Not reproduces by seed. The plant produces seed capsules that explode when touched, effectively ejecting its seeds. One plant can produce 2000 – 10,000 seeds, which can remain viable in the soil for 3 years.
The exploding seed capsules can cause the seeds to travel up to 3.4 m away from the parent plant. Longer-distance dispersal is generally caused by water flow or mowing after seed set. Lastly, humans are also responsible for the plant’s spread, as Smallflower Touch-Me-Not is still traded and planted for ornamental purposes.
Ecological, Economic, & Health Impacts
- Displaces native vegetation on stream banks.
- Increases ditch and stream bank erosion, because of its shallow root system and annual nature.
- Alternate host for crop pests such as cucumber mosaic virus.
- Contains naphthoquinone, which may cause mild to moderate irritation of the digestive tract.
- Infestations can choke drainage ditches, causing important infrastructure repair costs.
What Can I Do?
Smallflower Touch-Me-Not is currently found in the Sea to Sky, so PREVENTION of further spread is key:
Learn to identify Smallflower Touch-Me-Not: use the images presented on this profile page to learn how to identify Smallflower Touch-Me-Not.
What to do if you spot it: You can report any Smallflower Touch-Me-Not sighting by clicking here.
- Regularly monitor properties for weed infestations.
- Minimize soil disturbances and promptly revegetate disturbed areas to prevent the growth of Smallflower Touch-Me-Not.
- Check wildflower mixes to ensure that they do not contain Smallflower Touch-Me-Not.
- Ensure all flowering heads or buds are bagged or covered to prevent spread during transport to designated disposal sites.
- Unload, park or store equipment or vehicles in infested areas; remove plant material from any equipment, vehicles or clothing used in such areas and wash equipment and vehicles at designated cleaning sites before leaving infested areas.
- Plant Smallflower Touch-Me-Not in a garden, no matter how well-contained its enclosure may seem.
- Compost any flowering heads or buds. Instead, dispose of Smallflower Touch-Me-Not in the general/household waste stream at the landfill as the seeds may survive the composting process.
- Move soil, gravel, or fill that has been contaminated with Smallflower Touch-Me-Not.
- Smallflower Touch-Me-Not is relatively easy to control if it is pulled by the roots.
- The seed lasts in the soil for up to 3 years, so it is possible to control an infestation with a few manual removals.
- Pulling the roots from the soil is a less appealing option when the plants are growing adjacent to streams as a disturbance to the moist soil will likely cause stream bank erosion and possible alteration to the stream course.
- Smallflower Touch-Me-Not’s riparian habitat makes chemical control impossible.
- No biocontrol agents are currently available for Smallflower Touch-Me-Not in BC and further research is required.
- Dave’s Garden, Impatiens Species, Small Balsam, Small-flowered Touch-me-not, https://davesgarden.com/guides/pf/go/188046/#b
- Electronic Atlas of the Flora of British Columbia, Impatiens parviflora, http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Impatiens+parviflora
- Invasive Plant Atlas of the United States, Small flower touch-me-not, https://www.invasiveplantatlas.org/subject.html?sub=11725
- Invasive Species Compendium, Impatiens parviflora (small balsam), https://www.cabi.org/isc/datasheet/28768#tosummaryOfInvasiveness
- IPM Images, Small flower touch-me-not, https://www.ipmimages.org/browse/subinfo.cfm?sub=11725
- King County, Small-flowered jewelweed identification and control, https://www.kingcounty.gov/services/environment/animals-and-plants/noxious-weeds/weed-identification/small-flowered-jewelweed.aspx
- NatureGate, Small Balsam, http://www.luontoportti.com/suomi/en/kukkakasvit/small-balsam
- Plants for a Future, Impatiens parviflora – DC., https://pfaf.org/user/Plant.aspx?LatinName=Impatiens+parviflora
- US Department of Agricutlure, Weed Risk Assessment for Impatiens parviflora DC. (Balsaminaceae) – Smallflower touch-me-not, small balsam, https://www.aphis.usda.gov/plant_health/plant_pest_info/weeds/downloads/wra/Impatiens_parviflora_WRA.pdf
- Washington State Noxious Weed Control Board, Small-flowered Jewelweed (Impatiens parviflora), https://www.nwcb.wa.gov/weeds/small-flowered-jewelweed