National Geographic : 1920 May
COMMON MUSHROOMS OF THE UNITED STATES 419 i'hotograph by George Shiras, 3d THE PEAR-SHAPED PUFF-BALL (Lycoperdon piriforme) It is seen growing on and about the base of a tree (for another illustration of this species, see page 418). The plants are edible as long as the "flesh" is white. Photograph by A. G . and B. Leeper THE SKULL- OR BRAIN-SHAPED PUFF-BALL (Calvatia craniiformnis) One of the best, so long as the interior is white. Once the color changes, it is very bitter. Should be looked for in the autumn, in thickets by roadsides. About one-third natural size.