This week, I hiked at St. Josph’s Hill County Park, a hidden gem nestled between Novitiate Park and Lexington Reservoir County Park. During my hike, I was surprised by not only the spectacular views of the reservoir and the surrounding mountains but also the diverse array of plants in the park. While I was there, I saw everything from monkeyflowers to daisies to even silktassels. However, what struck me the most were the manzanita trees next to the trails.
Manzanita trees are interesting because unlike most trees, their bark is smooth and red instead of lumpy and brown. I wanted to find out more about this phenomenon, so I did some research, and I discovered that tannins are largely responsible for the trees’ reddish color. Tannins are molecules found in many plants, including corn plants, grape vines, and even grass. They’re the astringent molecules that cause your mouth pucker when you eat. Although they are not particularly toxic to humans in low concentrations, they are particularly toxic to many herbivores and microorganisms, so many plants, including manzanita trees, use these as a defense against herbivore.
However, although the tannins are responsible for trees’ bark color, they do not play a role in the bark’s texture. Although scientists don’t all agree on one reason for the manzanita trees’ texture, they generally agree that in the past, smooth bark offered better protection against herbivores and other invaders; for example, mountain pine beetles have a harder time climbing on smooth bark.
I never expected a hike to inspire my interest in manzanita trees, but that just goes to show that hiking is not only a great way to exercise but also a great way to fuel your curiosity!