"Galls cause worry for tree owners each year, but in truth, most of these odd-shaped growths are more of a curiosity than concern.
Galls have long been a part of tree life in Missouri and elsewhere in the central U.S. Some galls are small, pea-size growths on leaves. Others appear on twigs or stems and are persimmon-size and sometimes larger. Discover nature and learn more about galls with MDC and the Springfield News-Leader below." -- Lucas@MDC

Read the full article from the Missouri Department of Conservation