Some species, such as Penicillium digitatum on citrus fruits, and Penicillium expansum on apples, are common on specific foods, while others are less specialized and grow on many different kinds of food.
Some species, such as Penicillium digitatum on citrus fruits, and Penicillium expansum on apples, have specific food sources, whereas others are less picky and can grow on a range of edible items.