Some may grow gourds in the Lagenaria genus as well as the Luffa genus. These produce more prolific vines and require more space to grow than the Cucurbitas. Typical Lagenaria types include the dipper, club, bottle, kettle and powder horn gourds. They're the hard-shell gourds. Luffas are sponge gourds.
Many gourds get their common names from their shapes.
However, the shape, color and wartiness depend on many factors that gardeners have little control over. First, weather factors such as rainfall and temperature affect the gourd's characteristics. Gourds also have many genetic variations. Even gourds on the same vine may not be the same size, shape and color. Usually, color is the most variable among the traits.