ðɪs ɪz fəsˈɪlᵻtˌeɪɾᵻd baɪ ðə bˈʊlɪfˌɔːɹm sˈɛlz loʊkˈeɪɾᵻd æt ðə bˈeɪs ʌvðə vˈiːʃˈeɪpt nˈɑːtʃ wˌɪtʃ swˈɛlz ænd mˌeɪks ðə lˈiːf ʌŋkˈɜːl wɛn fˈɪld wɪð wˈɔːɾɚ.
This is facilitated by the bulliform cells located at the base of the V-shaped notch which swells and makes the leaf uncurl when filled with water.