MAD Cap Horse

     Naturalists often have "cheats" that they use to help them remember natural history facts. The saying "MAD CAP Horse" is such a saying, used to help in identification of native trees in the Mid-Atlantic. One of the basic steps in identifying trees is often figuring out whether they have alternate (staggered) or opposite (one twig directly opposite the other) branching throughout most of the tree. If the branching is opposite, then it eliminates many other possibilities, as there are far fewer woody plants with opposing branching systems. 

     So what does the mnemonic "MAD CAP Horse" stand for? Well, MAD corresponds with the Maples, Ashes, and Dogwoods, which almost all have opposite branches and twigs. There are a few exceptions, such as Alternate-leaved Dogwood, but it works for most native (and many non-native) woody plants throughout the Mid-Atlantic and many other locations. 

     "CAP" stands for the old family Caprifoliaceae, which was the family of mostly short shrubs like Honeysuckles, Viburnums, and Elderberries. Some have now reclassified them into other groups, but this work with the previous classification system that most people still know and recognize. 

     "Horse" stands for the Horsechestnut genus, which includes the buckeyes. Now the mnemonic isn't perfect, with things like Euonymus not fitting in and a couple of other exceptions, but it is still pretty reliable and can help a lot in classifying and identifying native trees. 

     And if you have to include Euonymus, I've even heard the saying "Uwanna MAD CAP Horse" and other versions. But for me, the classic naturalist saying has always stood me well when I was trying to identify trees and shrubs.