I was very excited to see an old friend, Ostrya virginiana, or American Hophornbeam, at a plant nursery last week:
I learned this plant in undergraduate school at Virginia Tech, but rarely see it this far north. The common name is due to obvious reasons -- the seed pods (technically the 'involucre') look a lot like hops (Humulus lupulus) flowers.
As you can see below, the habit is a bit scrubby, though fairly symmetrical. Ostrya belongs in that category of trees that are a bit small to be grouped in the shade tree category (maples and oaks, for example) but are too large to be categorized with smaller ornamental flowering trees.
Another shot of the involucre:
Perhaps what I most vividly remember noting when I was being taught this tree was its terrific, shaggy bark. It almost reminds me of the bark of a white oak (Quercus alba).
Finally, a direct shot of the leaves. Though large, the double serration makes the overall texture of this plant a bit softer. They don't get too showy in the fall -- the leaves take on a greenish-yellow hue, then drop.
Ostrya is in the Betulaceae family, which means it is related to Betula species , as well as Carpinus betulus. Like those species, this plant creates seeds with the use of male catkins.
Ostrya is derivative of the Greek word 'ostrua,' which means 'bone-like' (think of the related word, osteoporosis). This is definitely the case with American hophornbeam, whose wood is heavy and hard.