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).