Many species, such as the Louisiana quillwort and the mat-forming quillwort, are endangered species. The rare, spore-bearing plant quillwort was discovered in the area in 2004. Isoetes maritima, the maritime quillwort, is a quillwort in the Isoetaceae family. Consequently, many species of aquatic plants exist including water lobelia, quillwort and shoreweed. Isoetes occidentalis, the western quillwort, is a species of quillwort in the family Isoetaceae. Isoetes sinensis, the narrow quillwort, is a species of plant in the family Isoetaceae. Isoetes macrospora, the big-spore quillwort, is a species of quillwort in the Isoetaceae family. Quillwort species are very difficult to distinguish by general appearance. Isoetes brevicula is a quillwort species native to Western Australia. Isoetes bolanderi, or Bolander's quillwort, is a species of quillwort, a type of lycophyte. Isoetes louisianensis, the Louisiana quillwort, is a small, grass-like aquatic plant of the family Isoetaceae. The Louisiana quillwort occurs predominantly on sand and gravel bars on small to medium-sized streams. Isoetes nuttallii, or Nuttall's quillwort, is a species of quillwort, a type of lycopod.