Order Peronosporales is a group of fungi that are known to cause serious plant diseases. These fungi encompass a wide range of species, each with unique characteristics and impacts on crops. Some synonyms for the Order Peronosporales include the downy mildew fungi, the oomycetes, and the water molds. Each of these names refers to various aspects of the fungi, such as their fluffy appearance, reproduction, or aquatic habitat. The diversity of names used for this order of fungi reflects the complex nature of these organisms, and the many ways in which they can affect agricultural ecosystems. Understanding the synonyms for Order Peronosporales can help researchers and farmers stay attuned to the many threats posed by these fungi.