The Louisiana Quillwort (Isoetes louisianensis) is a small, grass-like aquatic plant of the family Isoetaceae. It occurs in only five locations in Washington and St. Tammany Parishes of Louisiana and some spots in southern Mississippi (USA). It is considered to be an endangered species, partly due to its highly restricted range. Scientific classification - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ... Divisions Green algae land plants (embryophytes) non-vascular embryophytes Hepatophyta - liverworts Anthocerophyta - hornworts Bryophyta - mosses vascular plants (tracheophytes) seedless vascular plants Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongue ferns seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering... Classes Lycopodiopsida - clubmosses Selaginellopsida - spikemosses Isoetopsida - quillworts The division Lycopodiophyta is a tracheophyte subdivision of the Kingdom Plantae that includes some of the most primitive of extant (living) vascular plants. ... In biology, binomial nomenclature is a standard convention used for naming species. ... Washington Parish is a parish located in the state of Louisiana. ... St. ... State nickname: Pelican State Other U.S. States Capital Baton Rouge Largest city New Orleans Governor Kathleen Blanco Official languages None; English and French de facto Area 134,382 km² (31st)  - Land 112,927 km²  - Water 21,455 km² (16%) Population (2000)  - Population 4,468,976 (22nd)  - Density 39. ... State nickname: Magnolia State Other U.S. States Capital Jackson Largest city Jackson Governor Haley Barbour Official languages English Area 125,546 km² (32nd)  - Land 121,606 km²  - Water 3,940 km² (3%) Population (2000)  - Population 2,697,243 (31st)  - Density 23. ... For other uses, see endangered species. ...

The Louisiana Quillwort occurs predominately on sand and gravel bars on small to medium-sized streams. These plants live for periods underwater. They are regularly inundated as much as 50 centimeters (20 inches) following rains, and may be inundated for long periods in wet seasons. Its habitat follows roughly along the Bogue Chitto River. The term habitat has a number of unrelated meanings: A concept in Ecology: see habitat. ...

Distinctive characteristics of this species include brown-spotted sporangial walls and megaspores with highly reticulate ridges, producing a spiny effect. Leaves are up to 16 inches long. The term spore has several different meanings in biology. ... In botany, a leaf is an above-ground plant organ specialized for photosynthesis. ...

The Louisiana Quillwort was discovered recently, in 1972, and was listed as an endangered species in 1992.