? Quillwort
Scientific classification
Kingdom: Plantae Division: Lycopodiophyta Class: Isoetopsida Order: Isoetales Family: Isoetaceae Genus: Isoetes
Species
See text Image File history File links Download high resolution version (1385x2325, 770 KB) Name Isoetes lacustris Family Isoetaceae Original book source: Prof. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms. ... Divisions Land plants (embryophytes) Non-vascular plants (bryophytes) Hepaticophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) Lycopodiophyta - clubmosses Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta - ginkgo Gnetophyta - gnetae Magnoliophyta - flowering plants Adiantum pedatum (a fern... 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. ...

Quillworts are plants of the genus Isoetes in the class Isoetopsida and order Isoetales. The order Isoetales is sometimes placed in the class Isoetopsida, sometimes in the Selaginellopsida or Lycopsida. They are considered "fern allies". There are about 140-150 species, with a cosmopolitan distribution but often scarce to rare. Some botanists split the genus, separating two South American species into the genus Stylites. Fern ally is a general term covering a somewhat diverse group of vascular plants that are not flowering plants and not true ferns. ... The term cosmopolitan refers to an individual who retains cultural roots in his or her country of origin, yet has adopted a wide taste for other cultures, and so lives both a local and global life. ... Botany is the scientific study of plant life. ...

Quillworts are mostly aquatic or semi-aquatic in clear ponds and slow-moving streams, though several (e.g. I. histrix, I. nuttallii) grow on wet ground that dries out in the summer. Quillwort leaves are hollow and quill-like, arising from a central corm. Each leaf is narrow, 2-20 cm long (exceptionally up to 100 cm) and 0.5-3 mm wide; they can be either evergreen, winter deciduous, or dry-season deciduous. They broaden to a swollen base up to 5 mm wide where they attach in clusters to a bulb-like, underground rhizome characteristic of most quillwort species, though a few (e.g. I. tegetiformans) form spreading mats. This swollen base also contains male and female sproangia, protected by a thin, transparent covering (velum), which is used diagnostically to help identify quillwort species. They are heterosporous. Quillwort species are very difficult to distinguish by general appearance. The best way to identify them is by examing the megaspores under a microscope. In botany, a leaf is an above-ground plant organ specialized for photosynthesis. ... A corm is a short, vertical, swollen underground stem of a plant (usually one of the monocots) that serves as a storage organ to enable the plant to survive winter or other adverse conditions such as summer drought and heat (estivation). ... A Silver Fir shoot showing three successive years of retained leaves In botany, an evergreen plant is a plant which retains its leaves year-round, with each leaf persisting for more than 12 months. ... Deciduous means falling off (deriving from the Latin word decidere, to fall off). ... Ginger rhizome In botany, a rhizome is a usually-underground, horizontal stem of a plant that often sends out roots and shoots from its nodes. ... This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... The term spore have several different meanings in biology. ...

Selected species

• Isoetes alpina New Zealand Quillwort
• Isoetes andicola (syn. Stylites andicola)
• Isoetes appalachiana Appalachian Quillwort
• Isoetes brochonii Pyreneean Quillwort
• Isoetes echinospora Spring Quillwort
• Isoetes flaccida Southern quillwort
• Isoetes gemmifera (syn. Stylites gemmifera)
• Isoetes histrix Land Quillwort
• Isoetes lacustris Lake Quillwort
• Isoetes louisianensis Louisiana Quillwort
• Isoetes melanospora Black-spored Quillwort
• Isoetes nuttallii Nuttall's Quillwort
• Isoetes tegetiformans Mat-forming Quillwort
• Isoetes tenella Spiny Spore Quillwort
• Isoetes tenuissima French Quillwort

Many species, such as the Louisiana Quillwort and the Mat-forming Quillwort, are Endangered species. In scientific classification, synonymy is the existence of multiple systematic names to label the same organism. ... Binomial name Isoetes lacustris L. The Lake Quillwort (Isoetes lacustris) is a plant in the quillwort family Isoetaceae. ... Binomial name Isoetes louisianensis The Louisiana Quillwort (Isoetes louisianensis) is a small, grass-like aquatic plant of the family Isoetaceae. ... The American bison numbered as few as 750 in 1890 due to extreme overhunting. ...

Quillworts are considered by some to be the last remnant of the fossil tree Lepidodendron with which they share some unusual features including the development of both wood and bark, a modified shoot system acting as roots, bipolar growth, and an upright stance. A fossil Ammonite Fossils are the mineralized remains of animals or plants or other traces such as footprints. ... Fossil trunk of Lepidodendron aculeatum showing leaf scars Lepidodendron (also known as the Scale tree) is an extinct genus of primitive, vascular, arborescent (tree-like) plant related to the Lycopsids (club mosses). ...

External links

• Species list (143 species)
• Flora of North America - Isoetes