Pecan

Arbor walk #54, TreeKeeper ID #1424

This Missouri native tree is predominantly found in the Mississippi River Valley, and in the American South where it is cultivated as an important commercial nut crop. The name “pecan” is an Algonquian Native American word, describing “nuts requiring a stone to crack.” The female flowers of the Pecan tree take about 8 years to mature and bear fruit. The state tree of Texas, a single pecan tree can live up to 300 years old and produces an average of 70-150 lbs. of pecans a year. Although enjoyed as a snack, pecans are important for wildlife as well; many animals such as birds, deer and squirrels rely on pecans as a food source. 

Common NamePecan
Latin NameCarya illinoinensis
Indigenous Name(s) Miami: kaanseenseemini; Quapaw: watástottá hi
Cultivar/Variety 
Commercial Name 
Global Distribution
Where to find Arbor Walk #54 on WashU campus
Our Pecan in space
GPS Coordinates

N/A

Percent Concrete

N/A

Distance to Buildings
YearClose Building #1Close Building #2Close Building #3
2020Hillman Hall, 19.13 mGoldfarb Hall, 37.56 mBrown Hall, 45.38 m
Distance to Other Species
YearClose Species #1Close Species # 2Close Species # 3
2020Bur Oak, 8.63 mNorthern Red Oak, 9.12 mElm Hybrid, 9.32 m
Our Pecan through time
Standard Measurements
YearHeight (m)DBH (cm)Caliper (m)Crown Diameter N-S (m)Crown Diameter E-W (m)Average Crown Diameter (m)
20207.058613.1N/A5.244.6
20239.725.5N/A6.656.616.63
Nests and Pests
YearDescription
2020Grey lichen and green algae on trunk bark
Trunk had a large open hole with a damaged, cracked area around it
How to identify a Pecan
Leaf Identification

The leaves are pinnately compound and alternately arranged on the stem. There are 7-17 leaflets per leaf, each between 2″ and 8″ long, with the largest leaflets halfway up the leaf.

Twig and Bud Identification

The twig turns from a light green color to a light gray-tan as it matures, with vertical white lenticels (pores) remaining. The terminal bud is covered in fine orange-brown hairs; it is obovate with a acuminate (tapering) tip.

Bark Identification

The bark is gray-brown with flaky scales and slight ridges.

Fruit Identification

The Pecan fruit is ovoid and green when immature, with the fruit dehiscing along the four ridged seams when brown and mature to release a singular hard-shelled nut. Inside this mottled brown shell is the edible pecan familiar to human palates.

Flower Identification

The flowers of the Pecan are dioecious but inconspicuous. The male flowers are hanging green catkins (long, slender clusters of flowers), and the female flowers are also green and located in small clusters near to the branch.

Relationship of Carya illinoinensis to other species in the arboretum
Additional resources on the Pecan

Take a look around Arbor Walk Tree #54