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Word of the Week: Pulvinus

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Welcome to Word of the Week! Stay tuned for a new word each Friday to amp up your nature vocabulary!

Pulvinus [ puhl-VAHY-nuh s ] (botany noun): A cushion-like swelling at the base of a leaf or leaflet. Acting as a joint, the pulvinus facilitates the growth and independent movement of an individual leaf or leaflet.

High Park is home to some really beautiful spruce trees, more specifically Norway Spruce. Norway Spruce is part of the Pinaceae family, which also includes many other trees that we see in High Park like pine trees, cedars, hemlocks, and larches. With so many trees from the pinaceae family present in High Park, how do you know which one is a spruce?

One of the ways in which we can identify a spruce tree is by looking at the needles. Spruce needles are attached to the branch by a pulvinus. On a spruce tree, the pulvinus kind of looks like a peg and allows for extra flexibility and movement. This identifying feature becomes extra obvious when a needle is dropped by the tree.

It is important to note that unlike the fascicles (or clustering needles) of a pine tree, each pulvinus holds only a single spruce needle. In addition, the pluvini will be arranged in a whorl, wrapping around the branch of the tree.

Keep an eye out for Norway Spruce on your next visit to High Park!