Life on the Outer Coast

Douglas Maple (Acer glabrum var. douglasii) is a deciduous tree that I mostly associate with Peril Strait and Shaman Island in Juneau. Arctos has a few records (Thatcher Point on Catherine island, Sitkoh Bay on Chichagof, Chaik Bay, Pybus Bay and Young bay on Admiralty island and Port Protection and Dry Pass on POW.

I first encountered maples in Alaska in 1981 near Neka Mtn on a limestone outcrop (other plants from the site include Polystichum lonchitis, Polemonium pulcherrium, and Asplenium trichomanes ramosum (viride) on a trip to the Eva islands on the Romance. That lone maple had a large canopy overhanging the beach. Over the years I’ve noticed a few trees along the Peril Strait shore (Lindenberg head, near Todd) in the fall when the leaves had turned bright yellow, but it encounters with native maple are rare for me.

On a trip to False Island this last weekend, I was lucky enough to find another one. Searching for plants wasn’t the goal of the trip, we were there to set up 4 deer exclosures to try to get at the effect of deer on vegetation in treated clear-cuts (thinned or gapped). At the end of the first day we were close to a beach and decided to spend a few moments on a sunny beach (young growth tends to be a bit dark). Fortunately, I can’t seem to resist walking down a beach and so found the maple. What drew me in was the luxurious growth of Lobaria pulmonaria on the trunks. It was only later that I noticed the opposite twigs (no leaves yet). Besides the Lobaria, the trunk had healthy growth of Metzgeria, Porella, and a bit of Ramalina (sp).

This small maple tree (to 5 m in Anderson and 10m in Pojar) is easy to recognize as such, it has pretty typical looking lobed leaves and samaras that most people associate with the genus. Characteristics that separate this variety of maple from the species include; red stems and shallowly lobed leaves with lobes > 6cm across. The flowers are yellow-green (not that I’ve seen them) as are the young v-shaped samaras.

Douglas maple is reported to be dioecious (separate staminate and pistillate flowers on the same plant), it seems like the ratio of male to female flowers on a given plant might be variable. The seeds are wind dispersed and reportedly have limited viability (?) and require a stratification period.

E-Flora BC has a nice photo and write up for this species.

Chris is about 6'4"