Investigations Into the Reproductive Biology of the Southern Appalachian Endemic Piratebush (Buckleya distichophylla): Pollination Biology, Fruit Development, and Seed Germination

Endemic to the mountains of Tennessee, North Carolina and Virginia, piratebush (Buckleya distichophylla, Santalaceae) is a rare, dioecious, hemi-parasitic shrub with a scattered and isolated distribution. Vegetative reproduction and few visible seedlings within the densest population of piratebush on Poor Mountain in southwest Virginia emphasize the need for research into this species' reproductive biology to inform conservation strategies. Pollination data showed no evidence for wind pollination; instead multiple diurnal floral visitors to staminate flowers were observed. Fluorescence microscopy of stigma and styles on initiated fruits revealed almost 95% with pollen deposition. Most initiated fruits (52%) had tube growth continue to the base of the style, indicating potential fertilization. Pollination experiments showed outcrossing was necessary for fruit set. Non-pollinated flowers in bags had 0% fruit development, whereas fruit development in both open pollinated (86%) (p< 0.0001) and hand pollinated (65%) treatments (p