Hawthorn (Crataegus spp.) is a small tree with round reddish or brownish lateral buds. The thorns are sharp. Voss and Reznicek list 29 species in this genus from Michigan but many are only shrubs.
Honeylocust (Gleditsia triacanthos) is a rare native in found in southern Michigan. It is planted widely including a thornless form (f. intermis). The twigs and trunk are armed with branched thorns. The terminal bud is absent and the lateral buds are hidden under the twig’s epidermis. Most trees will have a few seedpods that look like long, dark, flat, peapods (it is in the Fabaceae, Pea Family).
Wild Crab Apple (Malus coronaria), also called Sweet Crab, or American Crab is similar to Hawthorn. The buds are pointed and the thorns are blunt pointed. The thorns normally have leaf scars.
Black Locust (Robinia pseudoacacia) is not native to Michigan but widely planted and escaped. The terminal bud is absent and each lateral bud scar has a pair of stipular spines. The reddish buds are partially hidden by the epidermis.
Voss, Edward G. and Anton Reznicek. (2012). Field Manual of Michigan Flora. Ann Arbor: University of Michigan Press. (Crataegus on pp.811-819)
Copyright 2013 by Donald Drife
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