Wikipedia states: It is a large deciduous tree, growing to 20–40 m (65-130 ft) in height, rarely to 44 m (145 ft)[2]; taller trees to 50–55 m (165-180 ft) have been claimed but not verified. It typically has a spread of 12-23 m (40-75 ft) with a trunk up to 2 m (10 ft) diameter. A 10-year-old sapling will stand about 5 m (16 ft) tall. The leaves are alternate, 40–70 cm long, and pinnate with 9–17 leaflets, each leaflet 5–12 cm long and 2–6 cm broad. The flowers are wind-pollinated, and monoecious, withstaminate and pistillate catkins on the same tree; the male catkins are pendulous, up to 18 cm long; the female catkins are small, with three to six flowers clustered together. The fruit is an oval to oblong nut, 2.6–6 cm long and 1.5–3 cm broad.The nut itself is dark brown with a rough husk 3–4 mm thick that starts out green and turns brown at maturity, at which time it splits off in four sections to release the thin-shelled nut. Pecans, like the fruit of all other members of the hickory genus, are not true nuts but technically a drupe (fruit with a single stone or pit). The husks are produced from the exocarp tissue of the flower while the part known as the nut develops from the endocarp. Pecans first became known to Europeans in the 16th century; the Spanish explorer Cabeza de Vaca saw and wrote first about this plant. The Spaniards brought the pecan into Europe, Asia, and Africa beginning in the 16th century. In 1792 William Bartram reported in his botanical book, Travels, a nut tree, "Juglans exalata' that some botanists today argue was the American pecan tree, but others argue was hickory, "Carya ovata". Pecan trees are native to the United States, and writing about the Pecan tree goes back to the nation founders. Thomas Jefferson planted pecan trees, "Carya illinoinensis,' (Illinois nuts) in his nut orchard at his beautiful home, Monticello, in Virginia. George Washington reported in his journal that Thomas Jefferson gave him "Illinois nuts" pecans which grew at Mount Vernon, Virginia, George Washington's home. The nuts of the Pecan are edible, with a rich, buttery flavor. They can be eaten fresh or used in cooking, particularly in sweet dessertsbut also in some savory dishes. One of the most common desserts with the pecan as a central ingredient is the pecan pie, a traditional southern U.S. recipe. Pecans are also a major ingredient in praline candy, most often associated with New Orlean. In addition to the pecan nut, the wood is also used in making furniture, in hardwood flooring, as well as flavoring fuel for smoking meats.

Source of the commercial pecan; a tall, straight-trunked tree, fastest growing of the hickories; likes deep, rich soil; native to central midwest south to Mexico