Crooked Run Valley
Kentucky coffeetree (Gymnocladus dioicus)
Kentucky coffee tree
Gymnocladus canadensis Lam.
Guilandina dioica L.
CONFIRMATION STATUS: Confirmed.
TAXONOMY: The currently accepted scientific name of Kentucky
coffee-tree is Gymnocladus dioicus. Gymnocladus translates as "naked
branch", referring to its deciduous and bold character; dioicus translates
as "dioecious", referring to the predominately male and female tree forms
(sometimes alternatively spelled dioica).
NATIVE STATUS: Native, United States and Canada.
GENERAL BOTANICAL CHARACERISTICS: Kentucky coffeetree
is a large tree, maturing at about 70' tall by 50' wide, although specimen
trees in open areas can get much larger. It has an upright irregular growth
habit in youth (often being gangly, sparsely, and coarsely branched), but
becoming upright oval to upright rounded and symmetrical with maturity.
It has a rapid growth rate in youth, slowing to a medium growth rate with
maturity. It has a single trunk that soon gives rise to several main spread-
ing or ascending large branches. The bark is medium to dark gray, with
prominent overlapping plates on the branches and trunk. The twigs are
brown to gray, very stout and rough, irregular or contorted in its braching
pattern, and having huge alternate leaf scars. The twigs become scaly and
ridged at a young age, and with relatively few twigs per branch. The leaves
are alternate, bipinnately compound and very large, up to 3' long by 2' wide.
The leaflets emerge deeply bronzed, quickly turning to medium green and
then dark green or blue-green by mid-summer; each leaflet about 2" long,
ovate, arranged in alternate fashion along the pinnae, with 3 to 7 pairs of
pinnae arranged in opposite fashion along the huge rachis. The rachis (with
its swollen base) persists on the tree during early Winter, after leaflet and
pinnae abscission, but leaves behind a huge leaf scar upon abscission. Fall
color is usually chartreuse and (generally considered "ornamentally poor").
Staminate (male) and pistillate (female) inflorescences either occur on sepa-
rate trees (dioecious) or a mixture of unisexual (male or female) flowers and
bisexual (perfect) flowers occur on the same tree (polygamo-dioecious).
Female inflorescences are up to 10" long and pyramidally shaped, with the
males about one-third as large, both having green-white to blue-white
flowers and rather fragrant (but not noticed due to the height of flowering
branches on mature trees). The fruit is bold-textured purplish-brown
stout pods, 8" long and 0.75" thick, that mature in autumn on female or
polygamo-dioecious trees, containing seeds (with a very hard seedcoat)
embedded within the sweet and sticky pulp of the fruit. The pods dessicate
and persist in pendulous clusters from stout branches throughout much of
the winter (with abscised fruit litter being a maintenance chore to clean up
in late winter and early spring if tree is planted as ornametal).
REGENERATION PROCESS: Kentucky coffeetree propogates itself
by reseeding. Seed production varies; heavy fruit crops are not borne
SITE CHARACTERISTICS: Kentucky coffeetree is commonly found
on limestone soils and seldom found on unglaciated sites. It prefers contin-
uously moist, rich, deep soils in full to partial sun, but is very adaptable
and urban tolerant, especially to heat, drought, very alkaline pH soils, soil
compaction, and wet sites.
SUCCESSIONAL STATUS: Information pertaining to the successional
status of Kentucky coffeetree is limited. However, it has been terms a
"early to mid-successional species" for purposes of drought resistance by
researchers of the Warnell School of Forest Resources, University of
Georgia. It does not thrive in full shade, making it less tolerant of more
mature forest situations.
SEASONAL DEVELOPMENT: Inflorescences occur in late May and
early June, but are often hidden amongst the expanding foliage.
GENERAL DISTRIBUTION: The natural range extends from New
York and Pennsylvania west to Minnesota, southward to Oklahoma, and
east to Kentucky and Tennessee. The species is also found in the Dakotas,
Texas, Georgia, and the Carolinas; naturalized in Alabama, West Virginia,
Virginia, and Delaware. It is believed to have been introduced into some
areas by Native Americans.
SKY MEADOWS DISTRIBUTION:
Tree specimens can be found on trails marked in red.
Appalachian Trail/Old Trail
South Ridge/North Ridge
Rolling Meadows/ Lost Mountain
A single, planted specimen of Kentucky coffeetree occurs in front of
HABITAT TYPES AND PLANT COMMUNITIES: Kentucky coffee-
tree grows in moist soils in bottom-land woods or rocky open wooded hill-
sides with other hardwood trees. Kentucky coffeetree is uncommon in its
native habitat. It can only be found in small colonies in temperate forests.
The small colonies are of rather widely separated individuals resulting
from root suckers. Kentucky coffeetree can be found growing in associa-
tion with sweetgum, tupelo, oaks, and hickories, also black walnut, bass
wood, elm, and pawpaw in temperate forests.
IMPORTANCE AND USES: While the fruit of Kentucky coffeetree
seems to be of little value to wildlife, it does serve as a larval host and/or
nectar source for the bicolored honey locust moth (Sphingicampa bicolor)
and bisected honey locust moth (Sphingicampa bisecta).
Kentucky coffeetree is recommended for buffer strips around parking lots
or for median strip plantings in the highway as well as as a residential street
tree. It has also been used as a reclamation plant on waste sites.
Kentucky coffeetree is a favorite ornamental tree; it has long been use for a
shade, specimen, or focal point tree. It is highly appreciated because of 1) its
very bold year-round texture (especially in winter with its coarse branch-
ing, platy bark, and relatively few twigs), 2) ornamental bark, 3) ornament-
al fruit pods on female and polygamo-dioecious trees (before abscission), 4)
it is very urban tolerant and very tolerant of alkaline (calcareous, chalky, or
limestone-based) soils, and 5) is wet or dry site tolerant.
The reddish brown wood is hard and durable and very attractive when
finished and polished. It is used in cabinet making.
The brown seeds of Kentucky coffeetree were roasted or boiled and used
by the early American pioneers as a coffee substitute, hence the common
name. The raw leaves and raw seeds (but it is uncertain whether this
includes the fleshy, sweet pulp of the fruit pod) are potentially toxic to
mammals, including cattle and humans drinking water into which the
seeds have fallen.