Arbutus is a distinctive tree in our region, it is hard not to notice it with its smooth rusty-colored trunks and shiny green leaves. Very drought tolerant, it inhabits exposed rocky sites along the coast line, or rocky outcrops within a forest. It is our only evergreen broad-leafed tree, keeping its leaves on year round. Leaves that have become old and shaded by new growth are often shed in the summer.
Arbutus in its typical habitat – a rocky outcrop. Photo credit: Douglas Fraser
The bark of arbutus is one of its most distinctive features. The outer layer of the bark peels away in thin sheets every spring, revealing a smooth, initially green surface. Later in the summer, the green bark takes on a rusty-red color.
An arbutus stem in spring. The outer layer of bark peels off, revealing smooth green bark underneath. Photo credit: Douglas FraserBy summer, the green bark has taken on a rusty-red color. Photo credit: Douglas FraserVery old portions of the trunk, at the base of the tree, accumulate layers of bark and take on a dark-reddish brown cracked appearance. Photo credit: Douglas FraserWhy do arbutus trees shed their bark? It’s anyone’s guess. It is likely that the green bark has photosynthetic capacity in the spring. Compare the accumulation of lichens on the dead part of this branch, to the live (still shedding every spring) part. Perhaps shedding bark keeps trunks free from lichens and other debris. Whether this is adaptive or not is unclear. Photo credit: Douglas Fraser
Arbutus leaves are firm and leathery, the tree invests a lot of matter and energy in constructing them, they will last for a while. Leaves of mature trees have smooth edges, while seedling leaves have fine toothed edges – this can make identification of seedlings a bit confusing. The leaves are arranged in an alternate / spiral patterns along the stem.
Egg shaped shiny leaves of arbutus. Photo credit: Douglas FraserYou’ll often notice the meandering traces of the arbutus leafminer (Marmara arbutiella) on arbutus leaves. The larvae of this insect feed on the tissue in the center of the leaf (the mesophyll), while staying protected from predators by the tough outer layer (the epidermis) of the leaf. Photo credit: Douglas Fraser
Arbutus bears large clusters of white, somewhat fragrant, flowers in spring.
Cluster of arbutus flowers in spring. Photo credit: Lotus JohnsonCompare the urn-shaped arbutus flowers to those of salal and red huckleberry, and you’ll note the kinship among them – they are all members of the Ericaceae family, where many members have this flower shape. Photo credit: Douglas Fraser
After pollination, the flowers produce striking clusters of berries. Depending on the tree, these range from bright orange to deep red in colour.
Flowers pollinated in spring develop into clusters of orange berries that appear in early fall. Photo credit: Douglas FraserCluster of bright orange-red arbutus berries in fall. Photo credit: Cynthia CheneyClose-up of the leathery skin of arbutus berries. The berries are fleshy, but taste very astringent due to high tannic acid content. They do not appear to have been used much for food by First Nations people of our area. Photo credit: ME Sanseverino
