Digging for answers the causes and consequences of geophytism in the monocots


Meeting Abstract

37-3  Saturday, Jan. 5 08:30 – 08:45  Digging for answers: the causes and consequences of geophytism in the monocots HOWARD, C.C.*; LANDIS, J.B.; FOLK, R.; BEAULIEU, J.M.; CELLINESE, N.; University of Florida; University of Riverside; Florida Museum of Natural History; University of Arkansas, Fayetteville; Florida Museum of Natural History cchoward@ufl.edu http://www.codycoyotee.com

Geophytes are plants with resting buds that are located beneath the soil surface typically in the form of rhizomes, corms, tubers or bulbs. These adaptations are hypothesized to have evolved in response to an increase in climatic seasonality, and are highly diverse in areas like the Mediterranean Basin or the Cape Floristic Region. In addition to these hotspots, geophytes can be found across the globe and are distributed across the plant tree of life. However, geophytic taxa are most prevalent within the monocot clade and include members such as ginger, taro, arums and tulips. Interestingly, some clades appear to be more labile in underground morphology shifts while others are not. Despite this breadth of diversity, the majority of studies on geophytes have primarily focused on select clades or geographic areas; thus, broad phylogenetic inferences of these traits have yet to be carried out. Furthermore, it has been suggested that the switch to geophytism may promote increased diversification rates but this hypothesis has yet to be tested. Here, we investigate potential factors that have given rise to the diversity of underground organs that we see today. We ask: Are there any climatic variables that favor certain geophytes? How have these factors influenced the evolution of these taxa? Does geophytism promote diversification? Using a comprehensive phylogeny and global climate data, we investigate these questions in the monocot clade. While fine scale analyses are useful, unearthing broad evolutionary patterns of geophytism will allow for a more holistic view of the potential factors influencing their evolution, which is of utmost importance in order to promote further research of these complex structures and taxa.

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