Tuesday, October 30, 2012

The Canadian beer-tree

Species name: Ptelea trifoliata

Common name: hoptree, wafer-ash

Location: Ontario

The common hoptree or wafer-ash (named after the wafer-like fruit that persist on the tree until the following spring) is a rare species in Ontario, but the native range of the species doesn't extend far into Canada. Species become less and less common towards the limits of their range (whether the northern edge or the southern edge) since those habitats are less ideal than towards the centre of their range. There is the potential for this species to become more common as the climate changes, but there doesn't seem to be anywhere for this species to expand northward.

This species belongs to the Rue family, or the citrus family. It is the northernmost species of this family on any continent. When the young twigs or leaves are bruised or ground, they smell distinctly like lemons or oranges. Fantastic! The fruits look similar to the hop fruits normally used to flavour beer, and when used for that purpose the fruit of this species give a similar flavour (and hence the common name). The trees themselves rarely actually look like "trees," as in the first image above. The branching occurs very close to the base of the tree, giving it more of a bush-like appearance. For this reason, it's not a popular ornamental tree species, but would fit very nicely in a location meant for a shrub (but they can grow to be 8 meters tall under the right conditions!). They are not ideal for providing shade, since the branches don't fill out well towards the top of the plant. They're very..."sticky."