Classifying Ornamenal Plans ASK FOUR differen people wha he common name is for Liriodendron ulipifera, and you could possibly ge four differen answers. Naming organisms can ge very confusing. Over many years, scieniss have creaed logical sysems o classify and name plans. Objecives: 1. Discuss he classificaion of plans. 2. Explain he naming of plans. Key Terms: angiosperms annuals biennials binomial nomenclaure bryophyes conifers coyledon culivar deciduous dicos evergreen ferns genus gymnosperms herbaceous monocos morphology perennials species axonomy racheophyes variey vascular plans Classifying Plans The branch of biology ha deals wih idenifying and naming organisms is axonomy. Plans are classified based on he similariies of heir characerisics. Plan axonomiss compare flowering paerns, sem and leaf srucures, life cycles, geneic similariies, and many oher characerisics in deciding which plans are he mos closely relaed. The sudy of he form or shape of organisms or pars of an organism is morphology. E-uni: Classifying Ornamenal Plans Page 1 AgEdLibrary.com Copyrigh by CAERT, Inc. Reproducion by subscripion only. 030006
Taxonomiss use caegories o group plans. The caegories, from general o specific, are: Kingdom Division (Phylum) Class Order Family Genus Species Variey FIGURE 1. Taxonomiss use caegories o group plans. Culivar All plans are in he Kingdom Planae. Vascular plans, plans wih issue specialized for conducing maerials, are in he Division (Phylum) Tracheophya. There are many classes, orders, and families of plans. Differen scieniss have differen ideas abou how plans should be classified. As a resul, more han one classificaion sysem has been proposed. Soring ou he classificaion sysems can become confusing. A modern sysem ha has gained accepance is one presened by Rober Whiaker. Two major divisions wihin Kingdom Planae are Bryophya and Tracheophya. Those are furher subdivided. BRYOPHYTA Nonvascular plans, such as mosses, liverwors, and hornwors, are classified in Phylum Bryophya. Bryophyes end o live in damp places and are very limied in size because of he lack of conducing issue. They are someimes referred o as lower plans. TRACHEOPHYTA Plans wih vascular sysems consising of xylem and phloem FIGURE 2. Nonvascular plans, such as mosses, liverwors, and hornwors, are classified in Phylum Bryophya. E-uni: Classifying Ornamenal Plans Page 2 u AgEdLibrary.com Copyrigh by CAERT, Inc. Reproducion by subscripion only. 030006
are placed in Phylum Tracheophya. Tracheophyes may be seedless or seed-producing plans. Plans in Tracheophya ha reproduce wihou seeds are classified as perophyes. Seed-producing racheophyes are classified as gymnosperms or angiosperms. Perophyes Perophya is a class ha includes he ferns. Ferns are vascular plans ha reproduce by spores raher han seed. Some people call hem he amphibians of he plan world because hey are dependen on waer for heir sperm o swim hrough during reproducion. Ferns have no rue leaves bu have fronds. Fronds have he double purpose of food producion and spore formaion. They end o unfold from he cener of a plan, causing he newes fronds o be called fiddlehead. Gymnosperms Gymnosperms are plans whose seeds are no enclosed in an ovary. Mos gymnosperms reproduce using a srucure called a cone. Conifers, ginkgo, and cycads are considered gymnosperms. Conifers are gymnosperms ha produce cones. Examples are pines, spruces, and cedars. Conifer leaves are usually needles or scales. Mos conifers are evergreen, holding heir leaves all year round. However, some are deciduous, dropping heir leaves in he winer. Two examples of a deciduous conifer are he larch and he baldcypress. FIGURE 3. Spores on he boom of a fern frond. Angiosperms Angiosperms are plans wih flowers. They produce seeds ha develop wihin an ovary. There are wo subclasses of angiosperms, Monocoyledonae and Dicoyledonae. Monocoyledonae, or monocos, are plans ha have a single coyledon. A coyledon is a seed leaf ha sores food as sarch and proein for use by he FIGURE 4. The larch is a deciduous conifer. E-uni: Classifying Ornamenal Plans Page 3 AgEdLibrary.com Copyrigh by CAERT, Inc. Reproducion by subscripion only. 030006
Leaves: MONOCOT Long, narrow blades wih parallel veins Broad o narrow leaves wih need veins DICOT Flowers: Flower pars in muliples of hree Flower pars in muliples of fourorfive Sems: Vascular bundles scaered Vascular bundles arranged in circle Seedlings One seed leaf (coyledon) Two seed leaves (coyledons) FIGURE 5. Comparison of monocos and dicos. embryo. Monocos have flower pars in muliples of hree, parallel venaion on narrow leaves, and sems wih scaered vascular bundles. Examples are grasses, swee corn, and lilies. Dicoyledonae, or dicos, are plans wih wo coyledons in heir seeds. They have flower pars in muliples of four or five, need veins, and sems wih vascular bundles organized in a ring paern. They have broad leaves and include roses, peunias, and geraniums. LIFE CYCLES Plans are ofen classified based on heir life cycles. Gymnosperms and angiosperms reproduce by seed, bu hey use differen sraegies for passing on ha seed o fuure generaions of plans. E-uni: Classifying Ornamenal Plans Page 4 AgEdLibrary.com Copyrigh by CAERT, Inc. Reproducion by subscripion only. 030006
Annuals Plans ha complee heir life cycles wihin one year or one growing season are called annuals. Seeds of annuals germinae, and he plans produce leaves and roos, flower, produce seed, and hen die, all in less han a year. Many crops and garden plans are annuals. Corn, soybeans, rice, whea, poaoes, and omaoes are examples of annual food crops. Peunias, impaiens, marigolds, and zinnias are examples of annual garden plans. Many plans considered weeds, such as ragweed, pigweed, lamb s-quarer, and crabgrass, are annuals, oo. Biennials Biennials are plans ha normally require wo growing seasons o produce flowers and seed before dying. In he firs growing season, biennials grow vegeaively. In he fall, hey go dorman and res unil he following spring. During he winer monhs, hey receive a required cold reamen. Growh is resumed in he spring of he second season. The plans bol, flower, produce seed, and die. This group of plans is fewer in number han he oher wo groups classified by heir life cycles. Some examples include hollyhock, swee William, parsley, bees, and carros. Perennials Technically, perennials are plans ha have life cycles of more han wo growing seasons. Perennial plans may ake a few years o many FIGURE 6. Impaiens are annual garden plans. FIGURE 7. Hollyhocks are biennials. FIGURE 8. Almonds are woody perennial plans. E-uni: Classifying Ornamenal Plans Page 5 AgEdLibrary.com Copyrigh by CAERT, Inc. Reproducion by subscripion only. 030006
Annual Perennial Germinaion Growh Flowering Deah Germinaion Growh Flowering Dormancy Biennial One or more flowering cycles Germinaion (Season 1) Growh Dormancy Growh (Season 2) Flowering Deah FIGURE 9. Annual, biennial, and perennial life cycles. years o reach reproducive mauriy. They may be woody, like rees and shrubs, or herbaceous. Herbaceous plans have sof, nonwoody sems. Woody perennials may flower and produce seeds every year for many years. Woody perennial plans produce secondary growh ha persiss year afer year. Secondary growh gives he plans he abiliy o grow in girh and heigh. During he winer monhs, hey go dorman, or sop any growh. Plan growh resumes in he spring as vegeaive buds on he sems sprou. Examples of woody perennial plans are apples, maples, oaks, almonds, and oranges. The shoos of herbaceous perennials ypically die back o he ground each winer. The roos and crowns of herbaceous perennial plans survive and send up new shoos in he spring. Srawberries and asparagus are herbaceous perennials. Naming Plans Plans are named using a sysem called binomial nomenclaure. This classificaion sysem was developed by Carolus Linnaeus and uses Lain erms as scienific names for plans. A plan is commonly referred o by is genus name, which is always capialized, and is species name, which is always lef lowercase (e.g., Liriodendron ulipifera). Boh names are ialicized or underlined. A genus is a group of plans ha are very similar o each oher. A species is a group of plans ha have characerisics disinguishable from ohers wihin a genus and are so similar ha hey usually breed freely wih each oher in he wild. Plans are also called by common names. The common names for plans can vary from one region of he counry o anoher. For example, Acer saccharum is known in differen pars of he Unied Saes as sugar maple, rock maple, and hard maple. Scienific names are specific and remain he same hroughou he world. Alhough he sugar maple may be called a differen E-uni: Classifying Ornamenal Plans Page 6 AgEdLibrary.com Copyrigh by CAERT, Inc. Reproducion by subscripion only. 030006
common name in differen pars of he counry, he plan is recognized as Acer saccharum everywhere on Earh. Someimes culivaed plans wihin a species show a significan difference from oher plans in he species. These plans are called a variey. The difference is inheried from he previous generaion hrough sexual reproducion. The variey is wrien in lowercase, ialicized or underlined, and follows he specific epihe. A variey of sugar maple ha has a dense conical growh habi is wrien as Acer saccharum var. conicum or Acer saccharum conicum. Anoher group imporan o he horiculure indusry is culivar. A culivar has disinguishing characerisics from he oher plans in he species bu does no ransfer hose characerisics o is offspring hrough sexual reproducion. Culivars are propagaed by selecive hybridizaion or asexual means. A culivar of sugar maple is wrien as Acer saccharum Green Mounain. Summary: The branch of biology ha deals wih idenifying and naming organisms is axonomy. The sudy of he form or shape of organisms or pars of an organism is morphology. Taxonomiss group plans ino caegories: kingdom, division (phylum), class, order, family, genus, species, variey, and culivar. Nonvascular plans, such as mosses, liverwors, and hornwors, are classified in Phylum Bryophya. Plans wih vascular sysems consising of xylem and phloem are placed in Phylum Tracheophya. Plans in Tracheophya ha reproduce wihou seeds are classified as perophyes. Seed-producing racheophyes are classified as gymnosperms or angiosperms. Perophya includes he ferns, which reproduce by spores. Gymnosperms are plans whose seeds are no enclosed in an ovary. Angiosperms are plans wih flowers. Monocos are angiosperms ha have a single coyledon. Dicos are angiosperms wih wo coyledons in heir seeds. Plans are ofen classified based on heir life cycles. They may be annuals, biennials, or perennials. Plans are named using a sysem called binomial nomenclaure. Every plan is given a wo-par scienific name made up of is genus and is species. Culivaed plans ofen receive variey or culivar names as well. Checking Your Knowledge: 1. Wha caegories are used in plan classificaion? 2. Wha characerisics do plans classified as perophyes, gymnosperms, and angiosperms possess? E-uni: Classifying Ornamenal Plans Page 7 AgEdLibrary.com Copyrigh by CAERT, Inc. Reproducion by subscripion only. 030006
3. Wha are he hree life cycles of plans? 4. How are plans named? 5. How does a variey differ from a culivar? Expanding Your Knowledge: Idenify some common plans in your neighborhood by heir common names. Then, use resources o deermine he scienific names for your plans. Conduc furher research in plan classificaion. Find ou how your plans are classified from kingdom o culivar. Web Links: Inroducion o Planae hp://www.ucmp.berkeley.edu/plans/planae.hml Classificaion of Plans Whiaker Five Kingdom Sysem (1978) hp://home.manhaan.edu/%7efrances.cardillo/plans/inro/es.hml E-uni: Classifying Ornamenal Plans Page 8 AgEdLibrary.com Copyrigh by CAERT, Inc. Reproducion by subscripion only. 030006