Impatiens capensis, for example, has been observed to produce only cleistogamous flowers after being severely damaged by grazing, and to maintain populations on unfavorable sites with only cleistogamous flowers.
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However, preliminary results from Co-Extra, a current project within the EU research programme, show that although cleistogamy reduces gene flow, it is not at the moment a consistently reliable tool for biocontainment: due to a certain instability of the cleistogamous trait, some flowers may open and release genetically modified pollen.