Meeting Abstract
Plant bulbs are underground organs with resting buds located on a reduced stem surrounded by layers of leaves and/or scales. This trait has evolved at least eight independent times within the monocots. Iconic examples include tulips, hyacinths and onions. Although all bulbs are thought to be a common structure, there exists a diversity of bulb scale morphologies. Bulbs can be comprised of leaf bases, swollen scales, swollen leaf bases, or both leaf bases and scales. Additionally, external bulb morphology varies across taxa. Some are covered with a paper-like outer covering (i.e. tunicate bulbs [e.g., onions, tulips]) and others lack this trait (i.e. imbricate bulbs [e.g., lilies]). Furthermore, bulb size (i.e. diameter) varies greatly both within and among clades, with the Amaryllidaceae housing some of the largest bulbs and the Poaceae the smallest. The multiple independent origins of this trait provide researchers with an excellent opportunity to study the evolutionary and developmental processes that have promoted the evolution of these seemingly similar, yet morphologically diverse, structures. To generate evolutionary hypotheses of bulb evolution, in this study, we quantified bulb size variation across the monocots, and investigated potential underlying causes of size evolution.
