Correction: Doh! The information posted here about Manitoba maples is correct, but the accompanying photos are not of Manitoba maples, but Amur maples. Please see All Abuzz for the updated information.
At the southeast corner of Willow House, two trees form a graceful arch over the pathway to the door. They don’t have the sturdy trunk we usually associate with trees, but appear rather like two large bushes. They display the typical growth habit of the Manitoba maple (Acer negundo) or box elder, with branches forking near the ground into many crooked stems. In summer, the trees bear compound leaves quite unlike those displayed by other maples. However, the trees produce an abundant supply of dense clusters of maple keys, or samaras, which mark the species as a member of the Acer clan.
Native to the prairies, Manitoba maples grow along river valleys and floodplains, where their roots help to prevent erosion and their crowns shade streams, helping to maintain cool water temperatures for fish. Early settlers planted Manitoba maples with other trees to form shelterbelts that would help to break the winter winds and fight soil erosion. Millions of tree seedlings were distributed to prairie farmers by the Prairie Farm Rehabilitation Administration (PFRA) Shelterbelt Centre. Manitoba maples can also be used to produce maple syrup, and in recent years shelterbelt plantings have been evaluated as important carbon sinks.
Since the arrival of European settlers, the range of the Manitoba maple has expanded as far east as Nova Scotia. Its keys are a favorite food of the Evening Grosbeak (Coccothraustes vespertinus) and it is speculated that the planting of Manitoba maples may have played a role in the matching eastward range expansion of the grosbeaks.
In spite of the positive aspects noted above, Manitoba maples have long been disparaged as “junk” trees, disliked for their weedy, shrub-like growth, weak wood, susceptability to insect pests and messy dropping of leaves and keys. They are not, however, without their charms. That amazing, abundant crop of maple keys remains on the tree most of the winter. In the hush of a still winter evening, the merest breeze sets the keys in motion and the trees speak, a sweet, gentle, whispered “Shhhhhhhhhhhhhh!”.