Plant preparation
Cavitation in the leaves, petioles, petals, and peduncles was monitored
simultaneously in intact plants to determine the relative xylem
vulnerability and order of cavitation among reproductive and vegetative
organs within individual plants. Measurements of stem vulnerability were
completed separately on replicate plants to avoid excessive manipulation
(see below). Measurements were conducted on five replicate plants (3+
months old, ~1m tall) with fully expanded leaves and at
least two flower clusters with separate peduncles. Well-watered plants
were removed from pots and their roots were gently rinsed with water to
remove most of the soil. This ensured complete cavitation of all tissues
within 8 days. This duration ensured plant dehydration rates were fast
enough to capture embolism formation but slow enough to maintain water
potential equilibrium between slowly evaporating tissues (Bourbia et
al., 2020).