A
corn cob pipe's bowl is actually made from the hollowed out
cob of an ear of corn. The stem is made from hardwood. Early on (1860s) the Missouri Meerschaum factory had no problems finding suitable cobs. Now, corn kernels are eaten by people who like them large and sweet. The subsequent cob is small and narrow. The
University of Missouri was contracted to
hybridize a corn with a fat cob. Usually 150 acres of this hybrid keeps the factory in enough cobs for the year.
Homemade cob pipes were a rite of passage for Appalachian boys and some girls too. Hollow reeds were used for the stem. A variety of materials were used in the bowl if one couldn't afford the longed for Prince Albert in a can (the subject of that old phone gag, "Do you have Prince Albert in a can?" "yes" "Well, you better let him out before he suffocates").
Cob pipes can still be found for $1 - $2 in kitzy roadside stands up and down the US south, along with pecan rolls and little replicas of outhouses or wall plaques with a dry cob and a hammer stating "break glass only in emergency".