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Nonvascular (Hepatophyta, Bryophyta, Anthocerotyphyta) Nonvascular Plants Definition: Any of various plants that lack vascular tissue; a bryophyte Around 25,000 species of bryophytes all together Bryophytes used to be all the different types of nonvascular plants now it just includes moss Hepatophyta includes liverworts Anthocerotophyta includes hornworts Nonvascular plants are plants that do not use a system of vessels to transport water and nutrients between different parts of the plant Bryophytes (Mosses) Classifications There are 8 classes of moss Takakiopsida Sphagnopsida Andreaeopsida Andreaeobryopsidea Oedipodiopsida Polytrichopsida Tetraphidopsida Bryopsida Important Facts Approximately 12,000 species of moss Mosses are nonvascular and do not have roots meaning that then need moist environments so that water can be absorbed directly into the cells of the gameophyte In northern latitudes, the north side of trees and rocks will have more moss than others In the south, it’s the opposite Fossil records of moss are sparse Recovered as early as the Permian in Antarctica and Russia A moss plant body has no roots and has tiny cellular threads that serve as anchors The structures on moss look like a leaf although the "leaves" of the moss are only thin sheets of cells, usually a single layer The leaf like structures will curl up and dry out when water is unavailable and then revives when they obtain water Obtain energy through photosynthesis Description Small, soft plants usually around 1-10 cm (0.4-4 in) tall Commonly grow close together either in clumps or mats Mostly in damp or shady locations Produce spore capsules that may appear as beak-like capsules on thin stalks Are distinguished by their multicellular rhizoids Rhizoids-structure that functions like a root in support or absorption Life Cycle Begins with a haploid spore Spore germinates to produce a protonema Protonema is either a mass of thread-like filaments of flat Usually looks like a thin green felt and mainly grows on stable surfaces damp soil, tree bark, rocks, concrete or other From the protonema grows the gametophore (gamete-bearer) A single mat of protonemata can develop several gametophores which is what causes clumps of moss The tips of the gametophore stems or branches develop sex organs Female organs (archegonia)-small flask-shaped clumps of cells with an open neck that the male sperm swims down Male organs (antheridia)-enclosed by modified leaves called perigonium Mosses can either be dioicous or monoicous Life Cycle 2 Diocious- Male and female sex organs are on different gametophyte plants Monoicous or autoicous- both male and female sex organs are on the same plant When there is water, the sperm swim from the antheridia to the archegonia and fertilization occurs creating a diploid sporophyte Sperm has two flagellae the aid in propulsion The immature sporophyte pushes its way out the archegonial venter Takes about a quarter to half a year for the sporophyte to mature The sporophyte then develops a capsul and a operculum which are then sheathed by the remaing archegonial venter Inside the capsule, spore producing cells undergo meiosis to form haploid spores so the process can start over again Life Cycle Diagram Asexual Reproduction In some kinds of moss such as Ulota phyllantha, leaves or bits of the stem which break off and form new plants without fertilization This means all units are genetically identical Habitat Mosses are normally found in areas that are damp and have low amounts of light Some types of moss have adapted and are only found in cities Some types of moss are completely aquatic Common in wooded areas and near streams Also found in cracks in damp city streets Inhabiting bogs, marshes, and slow moving waterways Some types are semi-aquatics Wherever mosses are they require moisture Small size Lack of tissue and cuticule Need of liquid for fertilization Why is moss important? Supplies food and shelter for small animals and insects Protect soil Keeps slopes from washing away during severe weather or storms Help form new soil Anthocerotyphyta (Hornworts) Classifications Leiosporocerotopsida Anthicerotopsida Description Get their name from their horn shaped pore capsule Grow as a sheet of green tissue Without sporophytes present they are 10 to 20 mm in length Have no leaves or stem Attached to ground by rhizoid The plant body of a hornwort—the haploid gametophyte stage—usually grows thin rosette like or ribbon-like Between one and five centimeters in diameter Description Cont. Each cell in a hornwort usually contains just one chloroplast In most species of hornworts, the chloroplast is fused with other organelles to form a large pyrenoid Pyrenoids are the centers of carbon dioxide fixation within the chloroplasts of algae and hornworts that both manufactures and stores food The pyrenoids manufacture and store food This is unusual in land plants, but very common in algae Reproduction Reproduction in hornworts is the same as in moss The spores germinate into protonema which grows into a gametophore The gametophore then develops sex organs on the branches The antheridia then swims down the archegonia and fertilization occurs A diploid sporophyte then grows and the sporophyte develops a capsule with a spore inside Inside the spore meiosis happens so the cycle can begin again Habitat Hornworts can be found worldwide, but they usually grow only in places that are damp or humid Species can grow as weeds in gardens or fields Large tropical or subtropical species such as Dendroceros can be found on trees Hornworts are usually in the submersed plant community Since they lack roots they can drift to various water levels to find nutrients Tolerant of cool temperatures and low light levels Hepatophyta (Liverworts) Classifications Marchantiopsida Jungermanniopsida Haplomitriopsida-newly recognized class Important Facts 6000 to 8000 species Some species grow flattened and leafless called thallus Many thallus liverworts live on the surface of water Most species however grow in a leafy form The first liverworts were found 400,000,000 years ago during the Devonian Era Named a liverwort because the people that found them felt that the arrangement of cells on the surface was similar to cells from actual animal livers Description Small, ranging from 2-20 mm A flat, branching ribbon shaped plant that resembles the lobes of a liver Many different shapes of liverwort leaves: undivided, variously-lobed, divided into hair-like segments, or two lobes of unequal size Often used as indicators of the habitat condition Asexual Reproduction Certain species of liverworts produce vegetatively Liverworts contain bowlshaped structures call cupule Cupule holds gemmae which looks like little green eggs Raindrops splash gemmae onto the ground If the gemmae lands in a hospitable environment then it will develop rhizoids and produce liverworts Reproduction Same as moss and hornworts Archegonial receptacle from below with capsules filled with spores Spores will be released and if the conditions are right then the spores will germinate Life Cycle of Liverworts Habitat Mainly in deeply shaded, moist areas Such as under shrubs or plants Most common in the Northern Hemisphere Must be moist and have a source of water Some liverworts are aquatic and can live on the surface of water Desert species can tolerate direct sunlight and total desiccation Works Cited http://www.mainevolunteerlakemonitors.org/mciap/herbarium/ Hornworts.php http://www.teara.govt.nz/en/liverworts-and-hornworts/3 http://www.hiddenforest.co.nz/bryophytes/difference.htm http://www.essortment.com/all/mossplant_rmir.htm http://en.wikipedia.org/wiki/Hornwort#Life_cycle http://www.anbg.gov.au/bryophyte/classificationliverworts.html http://www.backyardnature.net/liverwrt.htm http://dermnetnz.org/dermatitis/plants/liverwort.html http://creationwiki.org/Hepatophyta
