One forestry teacher from my days at Michigan State University teacher stands out. He was the quintessential college professor–-quirky, compelling and brilliant–-and I absorbed all he taught like a sponge. Among other classes, he taught woody plant identification through the use of keys. Our class trailed him all over campus while we examined, sliced and occasionally tasted buds and twigs.
When keying woody deciduous plants, the first significant feature to discern is the arrangement of leaves on the steam, which can be alternate, opposite or whorled. The majority of plants are alternate and my crotchety, bud-eating forestry prof taught his students a trick, or sort-of acronym, for identifying plants with opposite leaf arrangements.
MAD Cap Horse.
It stands for M(aple)-A(sh)-(D)ogwood Cap(rifoliaceae) Horse(chestnut).
Plants in the genera of maples, ashes and dogwoods are opposite. Caprifoliaceae is the family that includes honeysuckles, snowberries, diervillas and weigelas. (Viburnums and elderberries were previously members of that family but are now included in the Axodaceae. What did the forestry prof do?) All members of the horsechestnut family also have opposite leaf arrangements.
This post also appeared in the Pine County Courier, Sandstone, Minnesota.