UNUSUAL SMOOTH RED BARK is common to both the manzanita bush and madrone tree which suggests they are related -- and they are. In fact they both shed layers of red-orange bark throughout the year, a characteristic that's unique in the plant world. But why do they do it?
It turns out that madrone tree - the manzanita's big cousin - has been around for millions of years dating back to the great forests, a time of dinosaurs, large birds and insects. To survive those voracious feeders, some plants adapted a smooth exterior bark which proved less tasty because it hosted fewer living organisms. Descendants of madrones, including the manzanita, continued to survive over time because of this smooth bark characteristic.
Smooth-bark trees have less protection than those with thicker rough exteriors, so they must have another way to protect themselves. The manzanita's outer layer peels away to prevent fungus and parasites, moss and lichens, from clinging to and destroying its trunk and branches. That's pretty cool!
Also, their red bark is high in toxic bitter-tasting tannins which deter insects, birds, and bacteria from penetrating the exterior and feeding on the tender tissue inside. Thus, the coupling of shedding bark and tannic compounds is really a survival adaption that madrones and manzanita have used to their advantage.
On the other hand, the bark is very attractive. It's impossible to resist the temptation to admire and touch the silky smooth red bark we find along the trail. That's one more reason to venture out into the wonderful wilderness here in California where there are more manzanita species than anywhere else in the world.