Poa paludigena is a species of grass known by the common names bog bluegrass, marsh bluegrass, slender marsh bluegrass, and Patterson's bluegrass. It is native to the northeastern United States. This perennial grass forms loose tufts of slender, weak, pale green stems up to 55 centimeters tall. It has no stolons and rarely has small rhizomes. The thin leaves are no more than 2 millimeters wide and 10 centimeters long. The inflorescence is an open panicle of just a few small spikelets. It is difficult to distinguish from related species without microscopic examination. It is similar to other Poa such as Poa compressa.