Comments

Marsh Muhly is a rather ordinary-looking grass that resembles Muhlenbergia frondosa (Common Satin Grass) and several other species in this genus. It can be distinguished from them primarily by its awned glumes, which are 6-8 mm. long. Other Muhlenbergia spp. in Illinois have glumes that lack awns, although their lemmas are sometimes awned. An exception is Muhlenbergia glomerata (Wild Timothy), which has awned glumes of the same length as Marsh Muhly; these two species are very difficult to distinguish. However, the anthers of Marsh Muhly are much smaller (about 0.5 mm. in length) than those of Wild Timothy (about 1.0–1.5 mm. in length), while the papery ligules of Marsh Muhly are longer (about 1.0 mm. in length) than those of Wild Timothy (about 0.5 mm. in length or less). There have been some attempts to make generalizations about the differing habitats that these two species are supposed to prefer, but this is rather risky because fidelity to any particular habitat appears to be low.