Horse chestnut (Aesculus hippocastanum)

South of Nash Hall Map

Similarities between this species and true chestnuts are few. True chestnuts have long, pointed, serrate leaves; horse-chestnut leaves are compound (five or more large ovate leaflets emerging from a single bud). The true chestnut has inconspicuous greenish-white flowers distributed in catkins; horse chestnut flowers are white, conspicuous and arranged on upright spikes. Horse chestnuts are vigorous and fast growing, planted for shade and ornamental value throughout much of North America (there are hundreds of horse chestnuts growing in Bellingham). Sadly, the true American chestnut (Castanea dentata), once the pride of eastern American forests and a source of a much-prized edible nut, since the 1930s has been reduced to the status of forlorn shoots emerging from rotting stumps by the voracious onslaught of Chestnut blight (Endothia parasitica). Only in the west, where Endothia has yet to arrive, is it possible to see chestnut trees in something approaching their former magnificence.

The main similarity between horse chestnuts and true chestnuts is that they both produce large, brown nuts. However, whereas true chestnuts are edible and choice, the horse chestnut produces a fruit that only squirrels can appreciate. Other examples of Aesculus hippocastanum are scattered about the WWU campus; several particularly healthy individuals are located across Highland Drive from College Hall.

Horse chestnuts are native to the Balkans. They were introduced into Western Europe as early as the 16th century and into North America in the 1740s. They are close relatives of the buckeyes, of which they are several native species. For instance, see the yellow buckeye.