Catalpa speciosa Warder
Coefficient of Conservatism: *
Coefficient of Wetness: 3
Wetness Index: FACU
Physiognomy: Ad Tree

Widely planted even into the Upper Peninsula, and sprouting in disturbed places, mostly in the southern Lower Peninsula, from the copious winged seeds produced; fields, dumps, fencerows, railroads, roadsides, parking lots, thickets, borders of forests, and along streams. First collected in 1893 in Jackson Co., though without a clear statement as to whether cultivated or not.

Small vegetative Catalpas are frequently seen on roadsides, shores, and disturbed areas. All our flowering and fruiting specimens of clear-cut escapes are this species, although C. bignonioides Walter has frequently been reported from the state. Catalpa speciosa is usually said to have larger corollas (limb 4–6 cm broad), odorless leaves, thicker capsules (12–15 mm wide), and bark on old trees fissured and ridged. Catalpa bignonioides apparently has smaller flowers (corolla limb 2–3 cm broad), leaves ill-smelling when crushed, capsules slenderer (5–10 mm wide), and old bark thin and scaly. Herbarium specimens lacking fruit and/or carefully pressed flowers as well as notes on odor and bark are inadequate for determination.

A single older (1934) fruiting collection from a roadside tree in Kalamazoo Co. does appear to be C. bignonioides, but it is not clear that this collection was not from a planted tree.


Allegan County
Berrien County
Calhoun County
Hillsdale County
Ingham County
Jackson County
Kalamazoo County
Kent County
Lenawee County
Livingston County
Macomb County
Monroe County
Muskegon County
Oakland County
Oceana County
Ottawa County
Shiawassee County
Washtenaw County
Wayne County


MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. November 29, 2022.