The biology of invasive alien plants in Canada. 9. Impatiens glandulifera Royle

Abstract

Royle (Himalayan balsam) is an invasive alien annual up to 3 m in height with showy flowers that are generally pink or purplish. Native to the Himalayan region, I. glandulifera was first recorded in Canada in 1901 in Ottawa, and is now found in eight Canadian provinces: British Columbia, Manitoba, Ontario, Quebec, Nova Scotia, New Brunswick, Prince Edward Island and Newfoundland. Impatiens glandulifera is typically found in riparian habitats and may spread rapidly because its seeds are readily transported via waterways. Up to 2500 seeds are produced per plant and dispersed explosively up to 5 m from the parent plant. This can result in dense monotypic stands which prevent establishment of native plants and make stream banks vulnerable to erosion when the shallow-rooted plants die back. Impatiens glandulifera is susceptible to glyphosate but because herbicide use in riparian areas is not advised, other control methods such as hand weeding, mowing or flaming have been used. Methods for eradication are most successful when upstream populations are controlled first, as the plants spread downstream. Removal of I. glandulifera should be managed synchronously with non-native control measures and ideally be accompanied by planting native species to ensure the restoration of native species composition. The prognosis for curbing its spread in Canada seems poor as it has quite rapidly become established along waterways in many regions, following a pattern seen over the past two centuries in Europe.Key words: Impatiens glandulifera, Impatiens roylei, Himalayan balsam, impatiente glanduleuse, policeman's helmet riparian, invasive plant, weed biology Clements, D. R., Feenstra, K. R., Jones, K. et Staniforth, R. 2008. La biologie des plantes exotiques envahissantes au Canada. 9. Impatiens glandulifera Royle. Can. J. Plant Sci. 88: 403Á417. Impatiens glandulifera Royle (impatiente glanduleuse) est une annuelle envahissante pouvant mesurer jusqu'a`trois me`tres de hauteur. Ses fleurs tre`s voyantes sont ge´ne´ralement roses ou mauves. Cette plante originaire de l'Himalaya a e´te´signale´e pour la premie`re fois a`Ottawa en 1901, mais on la retrouve ap re´sent dans huit provinces (Colombie-Britannique, Manitoba, Ontario, Que´bec, Nouvelle-É cosse, Nouveau-Brunswick, Iˆle-du-Prince-É douard et Terre-Neuve). Impatiens glandulifera affectionne habituellement les milieux riverains et se multiplie rapidement, car les cours d'eau en transportent aise´ment les graines. Chaque plant donnera jusqu'a`2500 semences qui seront disperse´es de manie`re explosive jusqu'a`5 me`tres de distance de la plante me`re. Il en de´coule parfois de denses peuplements monotypiques qui empeˆchent les plantes indige`nes de s'e´tablir et peuvent rendre les berges vulne´rables al 'e´rosion lorsque meurent ces plantes peu profonde´ment enracine´es. Impatiens glandulifera est sensible au glyphosate, mais l'usage d'herbicides e´tant de´conseille´dans les zones riveraines, on recourt a`d'autres me´thodes de lutte, notamment le de´sherbage manuel, la tonte ou le br...

Population genetics of an invasive riparian species, Impatiens glandulifera

“…We compare our results to those for H. mantegazzianum from the same catchments (Walker et al 2003). Because populations of I. glandulifera are often ephemeral (winter flooding can destroy them), there is no seedbank (Beerling and Perrins 1993;Clements et al 2008) and seeds are estimated to disperse twice as far along rivers , we hypothesize that disturbance will play a greater role in its distribution compared with H. mantegazzianum.…”

“…It was first recorded in northeast England in 1892 (Hulme and Bremner 2006). Although self-compatible, bumblebees are the primary pollinators and are capable of transferring pollen to plants several kilometres apart (Willis and Hulme 2004;Clements et al 2008). Inheritance of chloroplast DNA is entirely maternal (Van Went 1984).…”

The invasive Impatiens glandulifera Royle (Himalayan balsam) in the Republic of Macedonia: first record and forecast

“…Impatiens glandulifera Royle (Balsaminaceae), known also as the Himalayan balsam, is a herbaceous summer‐annual, widespread invasive plant species native to the Western Himalayas (Gupta, ; Tanner, ), which was established in North–Western and Central Europe (Beerling, ; Beerling & Perrins, ; Pyšek & Prach, ; Dawson & Holland, ; Weber, ; Peltre et al ., ), temperate North America (Toney et al ., ; Clements et al ., ) and New Zealand (Weber, ). In Europe, I .…”

Invasive plant species in the Swedish flora: developing criteria and definitions, and assessing the invasiveness of individual taxa

“…Among the 30 most problematic taxa in the present study, Impatiens glandulifera and Senecio inaequidens would be relatively easy to combat as they are easily uprooted and are easy to spot and identify. In addition, I. glandulifera is an annual lacking a persistent seed bank (Clements et al ) making it more vulnerable to single control actions. Thus, if a sufficient proportion of the population could be engaged to uproot these species whenever encountered, it might be possible even to exterminate them completely.…”