🌳Tree of the Month for August 2026

Howdy, park-goers! It's time for our August 2026 Tree of the Month. This month we're highlighting the Kentucky Coffeetree (Gymnocladus dioicus).

G. dioicus is a large, deciduous tree native to central and eastern North America, including our home state of Missouri. Specimens typically reach 60–80' in height and 40–55' in canopy width; however, I have personally seen specimens over 100' tall in the wild woods of southern Missouri and Illinois. In Missouri, this species prefers low and rich woodlands, bluff bases, and areas along streams and rivers.

G. dioicus is known for its rough, scaly gray-brown bark, large bipinnately compound leaves, and large seed pods (this species belongs to the legume family, Fabaceae). The foliage can reach up to 3' in length and is divided into 3–7 pairs of pinnae, with individual leaflets 1–3" long. Newly emerging leaflets appear in shades of pink or bronze-purple in spring before maturing to a pleasant blue-green for the growing season, then turning an undistinguished yellow and brown in autumn.

As the specific epithet implies, G. dioicus is a dioecious species, with individual trees being either male or female. Greenish-white flowers emerge in late spring (May–June): male flowers in racemes to 4" long, and female flowers in panicles to 12" long. The female flowers are fragrant and, once fertilized, give way to flattened, reddish-brown seed pods up to 10" long, which ripen in October and remain persistent throughout most of the dormant season.

Native Americans and early colonial settlers roasted and ground the seeds to brew a coffee-like beverage, hence the common name. The roasted seeds were also used as a food source, though raw seeds are highly toxic and should never be eaten fresh from the tree.

Find it in the Park

There are 60+ G. dioicus specimens throughout the arboretum at Tower Grove Park, making them one of the finest collections of the species in the Park.