Horticultural Classification WeedWeed –A misplaced plant! In England, certain daisies are considered a weed and here in the U.S., we cultivate themIn England, certain daisies are considered a weed and here in the U.S., we cultivate them Previously, sunflowers were considered a weed in the U.S. and now they are a major agronomic crop!Previously, sunflowers were considered a weed in the U.S. and now they are a major agronomic crop!

Horticultural Classification WeedWeed –Invasive: a plant introduced to an area where it displaces the native vegetation in an aggressive manner Exotic: a non-native plant, and not necessarily an invasive or weedy plant!Exotic: a non-native plant, and not necessarily an invasive or weedy plant!

Kudzu Introduced in 1876 at the Centennial exposition in Philadelphia, PA. Promoted by the US Soil Conservation Service during the 1930’s - They actually paid people to plant it!

Horticultural Classification Botanical System of Plant ClassificationBotanical System of Plant Classification –Based in the belief that plants evolved from a single organism –All plants are somehow related

Horticultural Classification Domain (a new classification!)Domain (a new classification!)Kingdom Division Division Class Class Order Order Family Family Genus Genus Species Species

Horticultural Classification 3 Domains:3 Domains: –1. Eukarya a. Kingdom Animaliaa. Kingdom Animalia b. Kingdom Plantaeb. Kingdom Plantae c. Kingdom Fungic. Kingdom Fungi d. Protists (certain algae, protozoans, slime molds having cell organelles)d. Protists (certain algae, protozoans, slime molds having cell organelles) –2. Bacteria (prokaryotes in multiple kingdoms) –3. Archaea (prokaryotes that live in Earth’s extreme environments. These also are in multiple kingdoms)

Horticultural Classification 5 Major Divisions of Plantae:5 Major Divisions of Plantae: –1. Pterophyta = ferns –2. Cycadophyta = cycads –3. Ginkgophyta = ginkgos –4. Coniferophyta = conifers –5. Angiophyta = flowering plants* *most commonly used as ornamentals by gardeners

Horticultural Classification 2 Major Divisions of Angiophyta:2 Major Divisions of Angiophyta: Monocotyledoneae = monocots (50,000 species) Dicotyledoneae = dicots (200,000 species)

Horticultural Classification Binomial System of NomenclatureBinomial System of Nomenclature –Developed by Linnaeus in 1753 –Italicize or underline the Latin name –Internationally recognized name regardless of language

Horticultural Classification Binomial System of NomenclatureBinomial System of Nomenclature –Ex: Acer rubrum = “red maple”

Horticultural Classification Ex:Ex: –Starrett mark –Starrett anne –Starrett bob –Starrett grace

Horticultural Classification Families (end in -aceae)Families (end in -aceae) –Pinaceae (pines, hemlock, spruce) –Ericaceae (rhododendrons, blueberries, azaleas) Genus (genera)Genus (genera) –Similar in structure, chromosome #’s SpeciesSpecies –Similar in structure, development and appearance, can sometimes interbreed

Horticultural Classification VarietiesVarieties –a distinct character separates this group of plants from the species –Often come “true-to-type” from seed

Brassica oleracea var. botrytis “cauliflower”

Brassica oleracea var. capitata “cabbage”

Brassica oleracea var. italica “broccoli”

Horticultural Classification CultivarCultivar –A “cultivated variety” –Plants have a distinct character that is retained when the plant is reproduced (generally vegetatively by cuttings) –Name is in ‘single quotes’ and Capitalized

Malus domestica ‘Delicious’

Malus domestica ‘Golden Delicious’

Horticultural Classification Clone - a genetically identical plant derived from a single mother plant by asexual propagation (cuttings or tissue culture)Clone - a genetically identical plant derived from a single mother plant by asexual propagation (cuttings or tissue culture)