Black Locusts of Appleton

by Neil Carleton 

The eight large Robina genus  pseudoacacia species, growing in a row along Wilson Street, in Appleton, are not pretending to be acacia trees.  False acacia, more commonly known as black locust, was named for its prickly resemblance to some trees of the Acacia genus – the thorntrees.  On our continent, black locust is native to south-western U.S.A. but has been widely planted as an ornamental tree and naturalized.  It’s a member of the pea family.  In Canada, black locust can be found in Nova Scotia, New Brunswick, Prince Edward Island, Quebec, Ontario, and British Columbia.

Black locust is a medium-sized tree, growing up to 25 m or 80 ft tall, with long compound leaves.  It’s similar in general appearance to the honey locust, but it doesn’t have the characteristic long-branched thorns on the trunk.  If you stop to admire the trees in Appleton, look for the pair of short spines at the base of each compound leaf.

Appleton Locusts 1 May 8 2013
On May 8, before the leaves were out, the irregular shapes of the black locust trunks and branches were evident at 242 Wilson Street in Appleton.
  Black locusts are one of the last trees to leaf out in our area.  On June 4 the row at Appleton was in full blossom.

Black locusts are one of the last trees to leaf out in our area. On June 4 the row at Appleton was in full blossom.

This tree reproduces by root suckers to form clones of interconnected trees.  Big, hanging seed pods form in the summer and stay on the tree until the next year.  Although the seeds rarely germinate, black locust is a large seed producer.  Like many other species in the pea family, the nitrogen-fixing bacteria of its root system enable the black locust to grow well in poor soil. 

In the spring black locust produces large, drooping clusters of fragrant, white flowers.
In the spring black locust produces large, drooping clusters of fragrant, white flowers.
On June 4 the roadside under the Appleton black locusts was covered with flower petals that had been dislodged by the wind.
On June 4 the roadside under the Appleton black locusts was covered with flower petals that had been dislodged by the wind.
  The crown of the black locust is open and the trunk is usually forked and crooked with rough bark.

The crown of the black locust is open and the trunk is usually forked and crooked with rough bark.
The bark on mature trees, like the row at Appleton, is brown-gray and deeply furrowed with a ropy texture of long, forking ridges.
The bark on mature trees, like the row at Appleton, is brown-gray and deeply furrowed with a ropy texture of long, forking ridges.

Thank you to Rob Cretain of Appleton for information about the black locust, Robina pseudoacacia.

 Do you have a notable or favourite tree?  Readers are invited to submit their nominations for an honor roll of trees in our area that could be featured in future articles.  You can contact me at 613-256-2018, <ve3nce@rac.ca>, or Neil Carleton, 3 Argyle Street, P.O. Box 1644, Almonte, Ontario, K0A 1A0.  I look forward to hearing from you.

My volunteer columns started in March 2010, as print features, to support the tree planting and tree awareness initiatives of the Mississippi Mills Beautification Committee.  The contact for the Tree Working Group is Ron Ayling, 613-256-4617.  In Carleton Place, the contact for the Urban Forest / River Corridor Advisory Committee is Jim McCready, 613-257-5853.

Until the next column, you’ll find me looking for and hanging out with shady characters.