Which type of fungi can grow in or on plants?

Obligate parasites are a type of fungi that depend entirely on their host plants for survival. They must grow in or on host plants to obtain nutrients, as they cannot live independently. This relationship can lead to various consequences for the plants, often resulting in disease or impaired growth. Obligate parasites have specialized structures that allow them to penetrate host tissues effectively and extract necessary nutrients.

Other types of fungi, such as saprophytes, primarily thrive on decaying organic matter and do not rely on living hosts. Mycorrhizal fungi form symbiotic relationships with the roots of plants, enhancing nutrient absorption but not causing harm to the plant. Ascomycetes represent a large group of fungi that includes both saprophytes and parasitic forms, but not all members of this group are obligate parasites. Therefore, obligate parasites are specifically characterized by their need for a living host to sustain their lifecycle.