Lycoperdon pyriforme, also known as Stump Puffball, is identified by its elongated pear shape, its smooth surface at maturity, white cords at the base, and its occurrence on woody substrates (other in genus grows on the ground).
often pear-shaped, but may also be nearly spherical. When very young covered in small white spines that typically fall off before maturity. Colour ranges from nearly white to yellowish brown with the darker shades developing with age. Spore mass at first white and firm, becoming olive-brown and powdery. Spores
Found in open, wooded areas, Lycoperdon lividium is also smooth, but is grayer and has warty spores (those of Lycoperdon pyriforme are almost smooth).
on the First Nature Web site.
on the MushroomExpert.Com Web site.