Tree Spotlight – No. 2 : The Oregon Maple


  • Acer Macrophyllum, the big leaf maple or Oregon Maple is a large deciduous tree in the genus Acer.
  • It can grow up to 48.89 meters (160ft 5in) tall, but more commonly reaches 15-2- meters (50-60 ft) tall. It is native to western North America, mostly near the Pacific coast, from southernmost Alaska to southern California.
  • It has the largest leaves of any maple,

  • It has the largest leaves of any maple, typically 15–30 cm (5.9–11.8 in) across, with five deeply incised palmate lobes, with the largest running to 61 centimeters (24 in). In the fall, the leaves turn to gold and yellow, often to spectacular effect against the backdrop of evergreen conifers.

  • The flowers are produced in spring in pendulous racemes 10–15 cm (4–6 in) long, greenish-yellow with inconspicuous petals. The fruit is a paired winged samara, each seed 1–1.5 centimeters (3⁄8–5⁄8 in) in diameter with a 4–5-centimeter (1 5⁄8–2-inch) wing.

  • Color/Appearance: Unlike most other hardwoods, the sapwood of maple lumber is most commonly used rather than its heartwood. Sapwood color ranges from almost white, to a light golden or reddish brown, while the heartwood is a darker reddish brown. Silver Maple can also be seen with curly or quilted grain patterns.

  • Grain/Texture: Grain is generally straight, but may be wavy. Has a fine, even texture. The growth rings tend to be lighter and less distinct in Soft Maples than in Hard Maple.

  • Rot Resistance: Rated as non-durable to perishable in regard to decay resistance.

  • Workability: Fairly easy to work with both hand and machine tools, though maple has a tendency to burn when being machined with high-speed cutters such as in a router. Turns, glues, and finishes well, though blotches can occur when staining, and a pre-conditioner, gel stain, or toner may be necessary to get an even color.

  • Odor: No characteristic odor.

  • Allergies/Toxicity: Bigleaf Maple, along with other maples in the Acer genus have been reported to cause skin irritation, runny nose, and asthma-like respiratory effects. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.

  • Pricing/Availability: Should be very moderately priced, though figured pieces such as curly or quilted grain patterns are likely to be much more expensive.

  • Sustainability: This wood species is not listed in the CITES Appendices or on the IUCN Red List of Threatened Species.

  • Common Uses: Veneer, paper (pulpwood), boxes, crates/pallets, musical instruments, turned objects, and other small specialty wood items.

  • Comments: Big leaf Maple is appropriately named, as its leaves (shown below) are the largest of any maple, commonly reaching an overall width of 6 to 12 inches (15-30 cm) across. Big leaf Maple is a commercially important hardwood timber for the United States’ west coast, where it is virtually the only commercial maple species in the region.

Science Notes: Lichen on Trees

We found lichen on many of the trees around the campus. And that’s very good for us, because lichens only grow where the air is clean. In the 1970’s there was almost no lichen to be found on trees in urban environments because of air pollution and acid rain.

Lichens are fascinating organisms. In fact they are not one organism at all. They are made up of a fungus and one or more algae living together in a mutually-beneficial relationship – a kind of mini-ecosystem. The fungus makes up most of what you see: it surrounds and protects the algae. In return the algae feed the fungus (which is unable to feed itself) by photosynthesis.

The beauty of lichens is not easy to see: you need at least a magnifying glass to appreciate them, but an electron microscope is even better. Here are two photos which Clodagh took of lichen on the Oregon Maples:

 Lichen fig1

In the top photo you can see the filament structure of the fungus. The small circular shapes in the bottom photo may be cells of the algae.

Lichens are great survivors. You find them all over the planet in many different environments. And it turns out that they can even survive in space! The European Space Agency arranged to take some lichen up to the International Space Station where they brought them outside, exposing them to the ultra-cold vacuum of open space, where they would be bombarded by cosmic rays and everything. No space suits for them, but they still survived the trip:



Trinity Ball – Trees cordoned off

Trinity College Trees Oregon Maple cordened off

When I called into Trinity College Dublin yesterday to meet and talk ‘Trinity Trees’ with David Taylor, David Hackett and Clodagh Dooley I was surprised to see many of the trees that are part of our project cordoned off in advance of the Trinity Ball which happens tonight.  I think they look great surrounded by the metal barriers – enveloped and protected.

Lichen images from March sampling

Lichen – The Oregon Maple

We found some wonderful examples of different types of lichen growing on some of the trees that were chosen.  The images above were taken from the bark of the Oregon Maple.  See below for a different type of lichen which we found on the Crab Apple tree. 


Lichen – The Crab Apple

Champion Trees of Ireland

Champion Trees - a selection of Ireland's Great Trees- the tree council of Ireland

Two of the trees from Trinity College Dublin feature in this beautifully illustrated book Champion Trees, a selection of Ireland’s great trees.

Platanus orientalis (Oriental Plane Tree), Trinity College Dublin – 4.98 x 11.5 meters.

Acer macrophyllum (Oregon Maple Tree), Trinity College Dublin – 3.68 @ 1.05 x 16 meters – 2nd greatest girthed of its kind in Ireland.

Of note is that the two Oregon Maples in the main square are also thought to be the oldest trees on the Trinity College Dublin campus.

Tree buds SEM images

The following images from the tree bud of the Oregon Maple are really interesting. The undulating surface of the seeds are of particular interest to me. Many years ago I completed a five foot plaster sculpture inspired by a similar seed structure. We may look further at these seeds to get a closer look at the surface and interior structure.

The Oregon Maple

During the sampling process in March we also got some wonderful SEM images from the buds of the Snake Bark and the Cherry Blossom.  See below.  I love the hairy thread-like structures sticking out of the buds.

The Snake Bark – tree bud

Cherry Blossom

Trinity College Trees Booklet

Trinity Trees book - front cover- Oregon Maple.jpg

Trinity College Dublin have compiled and printed a booklet entitled Trees of Trinity College Dublin. A third edition was printed in 2011 and it lists many of the trees to be found on campus. This booklet was jointly edited by David W. Jeffrey and Daniel L. Kelly, the later of which we are delighted to say will be consulting with us on some of the botany aspects of this project.

The booklet groups the various trees on campus into three sections. Each section is called a circuit and lists all the trees to be found in a particular area on campus. Circuit A encompasses the Front Square and Library Square. Circuit B includes trees situated in New Square and House 40 gardens. The final Circuit C covers all the trees in College Park.

Trees of Trinity College booklet-List of trees-tcd map-three tree circuts

Trees of Trinity College booklet also gives specific details on a select number of significant trees, three of which will be included in our project. These trees are the Hop Horn Beam, the Oregon Maple and the Cabbage Tree (Cordyline Palm). See below images of two of the listings in the booklet.

Trinity Trees book-Hop horn beam tree information.jpg

Trinity Trees book - Cabbage tree information