The mighty white oak

Species name: Quercus alba (hybridized with...?)

Common name: white oak

Location: Ontario

I took this photograph of a white oak on campus, and I doubt it's a "pure" white oak. The swamp oak (which you can read about HERE) and the white oak are not only very closely related species, but they also readily hybridize. For anyone to sell a "pure" white oak, I would like to know how they did it. Collecting acorns in the wild and growing up trees in a nursery (then repeatedly harvesting nursery acorns and replanting to grow up your stock) will almost always result in hybridized white oaks. And if the tree nursery also grows swamp white oaks, they've compounded their problem. In fact, oak pollen is so light and can travel so far on wind currents that you don't even have to know where a swamp oak or a white oak are to get them to hybridize. Like the issue with the Freeman maple (which you can read about HERE), once these two species hybridize they often get intermediate features, or a "blending phenotype." Oak pollen is actually one of the leading causes of seasonal allergies in the spring. Anyone living near an oak tree can attest to this; my dark grey car often takes on a yellow tinge because of our big red oak growing in the front yard.

The white oak, no matter its genetic background, has been used for centuries as one of the most prized woods in the world. Because of the structure of the cells in the wood, it is completely watertight when used for making furniture or other items. These same cellular structures make it rot-resistant, which is why it is so popular in the use of barrel construction; the liquid won't leak out of the barrel, and if it does start to become saturated with the liquid inside it won't rot and release the contents. Not cracking and breaking apart is probably preferred during the alcohol aging process! It's not just wine that's stored in oak barrels, but also rum and whiskey. Since some rums are aged for 20 years or more (an Appleton Estates rum to be released this year is a 75 year aged rum, all done in oak barrels), putting them in a barrel that's likely to rot or leak is probably not preferred! The watertight and rot-resistant characteristics also make oak a popular wood historically for shipbuilding and agricultural construction (both equipment and barns).

On the inside of homes, oak is a popular wood for visible finishings. Sometimes cabinets are made out of a different kind of (cheaper) wood, then the front facings are oak. Oak flooring is also incredibly popular, and often it's even stained to resemble other, more expensive woods (like cherry, walnut or mahogany). In fact, most mahogany flooring sold today in Canada is just white oak wood stained a reddish colour, since international trade treaties have been signed preventing the import of South American tropically-grown mahogany wood into Canada. Since the term "mahogany" doesn't actually apply to any one species of tree (unlike wood from black walnut, white oak, sugar maple, white pine, etc.), that eliminates many options for sourcing mahogany! While I'm sure mahogany is incredibly popular to use for fine furniture and household finishings, South American rain forests are being eliminated at an alarming rate for both the international wood trade, and conversion to the North American style of farming (higher productivity for a few years, but then a drastic decline in productivity due to the low level of nutrients in the soil). By preventing the import of these trees, we are doing our part in attempting to conserve the tropical forests in South America.

There are some notable famous white oaks across the United States. The first isn't one tree, but actually an entire grove of white oak trees. The USS Constitution is made entirely of white oak, and whenever parts of it need to be replaced they come from a grove of trees called Constitution Grove near Bloomington, Indiana. The states of Connecticut, Maryland and Illinois have all made the white oak their state trees, with one specific oak representing the honorary tree of the state. The Charter Oak in Connecticut is even featured on the back of their state quarter (which I, of course, proudly own since it features a botanical design). The honorary state tree of Maryland, the Wye Oak, was one of the oldest living trees in the United States until it was destroyed in a storm in 2002. In Illinois, they couldn't decide which tree they liked better to serve as their honorary white oak so they picked two; the first is on the front lawn of the governor's house, and the second is in a school yard. The new largest living white oak is the Linden Oak, also located in Maryland.

Once upon a time Freeman made a maple

Species name: Acer x freemanii

Common name: Freeman maple

Location: Ontario

Technically speaking, the Freeman maple isn't actually a species at all, but rather a hybridization between a red and a silver maple that happens often in nature when the two species are present in the same location (which is often; their native ranges overlap almost completely). Depending on whether it's silver maple pollen or eggs, you can get drastically different phenotypes (or appearances of the tree). I'm betting that this tree was produced as a result of red maple pollen and silver maple ovules (eggs); the characteristics of this tree are almost identical to the silver maple except for the bright red petiole of the leaf. In fact, this tree is labeled as a silver maple on campus, but I have my doubts. If it was truly a silver maple with no hint of a hybrid, it would have green petioles and would be turning a yellow-green in the fall, not red.

So why would you want to hybridize a red and silver maple? Well, the silver maple grows very quickly, and so provides shade to an area faster than a red maple would which is often a desirable outcome of planting a tree. The downside of the silver maple is that their roots can often be quite invasive. They don't grow very deeply into the soil, and can bubble up concrete or asphalt easily which is not always a desired outcome. The red maple has much deeper roots that don't creep along the soil surface, so there is less of a chance of destroying nearby sidewalks, roads or driveways. The wood of the silver maple is also incredibly brittle. Normally this doesn't matter since many people enjoy the tree and not the lumber at the end of the day, but silver maples also have another dirty secret: they're almost always hollow due to heart rot (a fungal disease where the fungus targets the old, dead wood on the inside of the tree that is used for support). This is great for wildlife who require hollow trees to nest, but terrible for your house or garage during a wind storm; trees shown on TV that have crushed cars or houses after a violent storm (not a tornado) are often silver maples. This doesn't happen with red maples. Their wood is much more durable, and they are less likely to get heart rot and so are less likely to be destructive during a bad storm. The last reason why you might want to hybridize the two species is because of the aesthetic factor; bright red petioles are much prettier than just plain old green ones. Depending on the number of generations since the initial hybridization, the leaves might also turn a brilliant yellow-orange during the fall instead of the silver maple's boring yellow-green. You never quite achieve the neon red of the red maple's fall coloration, however.