I last wrote about honey locust trees (Gleditsia triacanthos, Fabaceae) back in the warm month of September, when these trees were lush and green. Now that we’re in the depths of winter these deciduous trees have gone through senescence and entered dormancy. One notable feature from these trees remains apparent, however.
As members of the legume family (which also includes peas, beans, alfalfa, peanuts, and licorice), honey locusts produce their seeds in dry fruit known as pods. At the northern extreme of its range here in Michigan, this tree flowers in late May or June. Pollination is performed by insects (especially bees), and following fertilization the seeds begin to develop. By October the seed pods have ripened, and they slowly begin to fall from the trees.
Here, in early December, most of the pods were still attached to the trees. By the end of December, most had fallen and littered the ground. Dense collections of long, twisted, red pods make it obvious that there’s a honey locust nearby. If you aren’t staring at the ground, the enormous thorns on the trunk and branches are also a dead giveaway.
The pods have a sweet flavor (hence the name “honey” locust) that attracts birds and mammals. These animals help to distribute the seeds over a wider area. The tough seed coats prevent the seeds from being digested, and the trip through an animal’s digestive tract may help increase germination rates.