Persea palustris, also known as swamp bay or swampbay, is a small tree or shrub found throughout the Southeastern United States and the Bahamas, with much of its range overlapping with that of its relative Persea borbonia. It is generally not more than 40 feet tall, with bark separated into scales by fissures across its surface. Mature leaves are green, paler on their undersides, which have prominent brownish or reddish-brown hairs. The species prefers swamps and coastal areas, particularly locations with moist, peat-rich soil. It is sensitive to the fungal disease known as laurel wilt, even more so than related species.

Laurel wilt, also called laurel wilt disease, is a vascular disease that is caused by the fungus Raffaelea lauricola, which is transmitted by the invasive redbay ambrosia beetle, Xyleborus glabratus. The disease affects and kills members of the laurel family. The avocado is perhaps the most commercially valuable plant affected by laurel wilt.