Phytophthora ramorum is a plant pathogen known for causing Sudden Oak Death, a disease that affects various tree species, particularly oaks. It thrives in moist environments and spreads through water, soil, and infected plant material. The pathogen can lead to significant tree mortality and has serious ecological and economic impacts. This organism is a type of water mold, belonging to the genus Phytophthora. It can infect a wide range of host plants, including ornamental species and native flora. Effective management strategies include monitoring, sanitation, and the removal of infected plants to prevent further spread.