Abstract
Impatiens pallida, a succulent annual herb of moist temperate forests, typically wilts on summer days after several minutes of direct sunlight. Time courses of gas exchange and leaf water potential were measured to determine if wilting resulted in substantially reduced photosynthesis, stomatal conductance, or leaf internal CO2 concentrations. Leaves quickly wilted with the onset of high‐light, but photosynthesis and stomatal conductance increased markedly. Photosynthetic rates and stomatal conductance declined slightly after several hours of high‐light, and from morning to late afternoon shade conditions. Leaf internal CO2 declined with increased photosynthesis, but there was no evidence that stomatal conductance limited photosynthesis through the day. We propose that rapid wilting is an adaptation that facultatively limits heat loading and extreme water loss under high‐light. Further whole plant studies in natural settings are needed to fully evaluate the quantitative significance of wilting in relation to water use and photosynthesis.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
