Life: The Excitement of Biology 3(2) 83 Molecular Classification of Exudates from the Monocots, Magnoliids, and Basal Eudicots 1 Joseph B. Lambert 2 , Connor L. Johnson 2 , Allison J. Levy 2 , Jorge A. Santiago-Blay 3 , and Yuyang Wu 4 Abstract: This study provides molecular classifications by nuclear magnetic resonance spectroscopy for exudates from the monocots, the magnoliids, the basal eudicots, and core eudicots other than rosids and asterids. The monocots and magnoliids diverged prior to the eudicots from the angiosperm lineage. Our analyses include 78 samples from 10 orders and 14 families. The magnoliid exudates have diverse molecular origins. Within the monocots, the genus Aloe of the Xanthorrhoeaceae provides a conserved phenolic exudate that is different from the class called kinos and is proposed as a new class. Within the commelinid clade of the monocots, exudates of the Arecales (palms) are primarily gums, whereas those of the Poales (grasses) are diverse. A single sample from the Ranuncales within the basal eudicots is phenolic. The core eudicots (other than rosids and asterids) include the Saxifragles, from which the storax exudate of the genus Liquidambar of the Altingaceae is a terpenoid resin, not a phenolic material as previously reported. Also from the core eudicots, exudates from the Cactaceae of the Caryophyllales primarily are gums. Key Words: aloes, eudicots, gums, gum resins, kinos, magnoliids, monocots, NMR, phenolics, plant exudates, resins Introduction Plant exudates comprise a chemically diverse group of materials that are released usually in response to trauma due to damage, disease, or drought. They appear most obviously on the trunk and branches of trees and shrubs but also may appear on leaves, stems, and roots, as well as well as with other types of plants (Lambert et al. 2013a). Although sap and nectar formally are included, we generally restrict our investigations to exudates that solidify to a robustly stable material, usually in hours to days. Such stable solids may be stored safely for years and may be studied in either the solid state or in solution. Solid plant exudates have played an important role in human culture for millennia (Rodríguez et al. 2013), including as incense, jewelry, medicinal products, food, 1 Submitted on June 11, 2015. Accepted on July 3, 2015. Last revisions received on July 23, 2015. 2 Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas 78212-1200 USA. E-mail: jlambert@northwestern.edu 3 Department of Paleobiology, National Museum of Natural History, Washington, District of Columbia 20560 USA. E-mail: blay@si.edu 4 Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, 60208-3113 USA. E-mail: y-wu1@northwestern.edu DOI: 10.9784/LEB3(2)Lambert.01 Electronically available on July 27, 2015. Mailed on July 25, 2015.