|The characteristic blunt leaf of the Liriodendron|
A neighbour once asked me whether she should worry about tree roots invading her drains if she selected a “yellow poplar” through Toronto’s street tree program, as poplar roots are notorious for their water-seeking ways. I assured her that the yellow-poplar isn’t actually a poplar, but (along with whitewood) simply one of the assorted common names for Liriodendron tulipifera, the native North American tulip tree.
‘Liriodendron’ means lily tree and ‘tulipifera’ means tulip-making, both in relation to the large-ish, single flower – as you might expect from a member of the magnolia family. So tulip tree is a much more appropriate common name. Unfortunately, you’re unlikely to see this attractive green and yellow or orange tulip-y bloom until the tree is about 15 years old, or 20 feet/6.5 meters tall – and, even then, they often appear near the top of the tree, where it’s hard to appreciate their form. Unless you’re a bee. Tulip trees are very attractive to bees.
|Tulip tree leaves catching the light, and the silhouette of a visitor|
Nevertheless, I’m inordinately fond of the tulip tree, if for no other reason than their unusually shaped leaves, with their truncated apex. This distinctive leaf shape is the easiest way to recognize Liriodendron during the growing season. Tulip trees are being planted more frequently, and it always delights me to encounter one. The large, mid-green leaves can glow in the sunlight, and in fall can turn a rich shade of gold.
This is a fairly adaptable tree when it comes to growing conditions and climate. In Southern Ontario, we’re at the northern limit of its native zone, which stretches all the way down the eastern continent to Florida. I’ve seen it listed as both shade-intolerant and somewhat shade tolerant, so I suspect culture has an impact on this. Like many of the most attractive forest dwellers, tulip tree does best in deep, rich, moist, slightly acidic soil, where it can grow to a significant size fairly rapidly.
For more info on and pictures of Liriodendron, drop by Walter Muma’s useful Ontario Trees and Shrubs website. To download a brochure on Toronto’s street tree program, visit the City of Toronto Urban Forestry page.