Plant Taxonomy By: Scott A. Brady

SSHS Science

Plant Characteristics • Review of what we already know

• Will help in identifying plants

Identifying Plants

•  Physical characteristics are used to identify plants which include…. •  Life Cycle •  Form •  Foliage Retention •  Plant Parts •  Use & Location

Life Cycle

•  Annuals •  Plants that complete their life cycle in

one year. •  Biennials

•  Plants that complete their life cycle in two years.

•  Perennials •  Plants that live more than two years.

Growth Habits

•  Trees •  Shrubs •  Vines

Growth Forms

•  Columnar •  Spreading •  Weeping

•  Round •  Oval •  Pyramidal

Growth Forms

Spreading

Columnar

Weeping

Growth Forms

Round Oval Pyramidal

Foliage Retention

•  Deciduous •  Loses leaves during the dormant season.

•  Evergreen •  Keeps leaves and remains green year-

round.

Plant Parts – Leaf

•  Arrangement •  Shapes •  Color •  Vein Pattern •  Form – Simple or Compound •  Margin •  Surface

Leaf Arrangement – Simple

Leaf Arrangement – Compound

Leaf Shape

Vein Pattern

• Pinnate • Palmate • Parallel • Dichotomous

Leaf Margin

Leaf Surface

•  Glabrous •  Pubescent •  Villous •  Tomentose

•  Scabrous •  Glaucous •  Rugose •  Glandular

• There are 8 common leaf surfaces.

Leaf Surface – Glabrous

•  The surface is smooth, not hairy.

Leaf Surface – Pubescent

•  Short, soft hairs cover the surface.

Leaf Surface – Villous

•  Long, straight hairs cover the surface.

Leaf Surface – Tomentose

•  Covered with wool-like hair.

Leaf Surface – Scabrous

•  Covered with short, prickly hairs.

Leaf Surface – Glaucous

•  Covered with a bluish-white waxy substance.

Leaf Surface – Rugose

•  Surface is wrinkly.

Leaf Surface – Glandular

•  Glands filled with oil or resin cover the surface.

Plant Parts – Flowers

• Color • Shape • Size

Plant Parts – Bud & Stem

•  Shape & Color •  Stem Modifications

•  Thorns •  Spines •  Prickles

Plant Parts – Modified Stems

Thorn

Prickle Spine

Plant Parts – Roots

•  Tap •  Fibrous •  Bulb

Plant Parts – Roots

Tap Root

Tuberous Root

Fibrous Root

Plant Parts – Fruit

•  Cones •  Nuts (Acorns) •  Pomes (Apple) •  Drupes (Peach)

•  Brambles (Raspberries)

•  Capsules (Willow) •  Samara (Maple)

Plant Parts – Fruit

Cones

Acorns

Pomes

Plant Parts – Fruit

Drupes

Brambles

Capsules Samara

Use & Location

•  Not absolute, but helpful. •  Indoor or outdoor. •  Altitude •  Wet or dry •  Hardiness Zone •  Sun, partial shade, or shade. •  Landscape purpose – specimen, border, etc.

Plant Taxonomy

Introduction

•  Taxonomy is the science of classifying and identifying plants.

•  Scientific names are necessary because the same common name is used for different plants in different areas of the world.

•  Latin is the language used for scientific classification.

Karl von Linne (1707-1778)

•  Swedish botanist •  Developed binomial

classification scheme for plants.

•  Uses two Latin words to indicate the genus and the species.

•  Changed his name to the Latin name of Carolus Linnaeus.

Scientific Names

•  The first word is the genus and the second word is the specific epithet.

•  If there are additional words, they indicate the variety or cultivar.

•  Some scientific names bear the name of the person who first named the plant.

Examples

•  Citrullus lanatus (Thunb.) Mansfeld • Watermelon

•  Astragalus alpinus L. •  Alpine Milkvetch

•  Primula incana Jones •  Silvery Primrose

•  Poa Bulbosa L. •  Kentucky Blue Grass

Genus

•  Plants in the same genus have similar characteristics.

•  Examples: •  Quercus – Oaks •  Acer – Maples •  Pinus – Pines •  Ilex – Hollies •  Cornus – Dogwoods •  Ficus – Figs

Scientific Classification

•  The broadest category of scientific classification is the Kingdom. •  Either Plant or Animal

•  The broadest category of the plant kingdom is Division or Phylum.

Scientific Classification

Kingdom

Phylum/Division

Class

Order

Suborder

Family

Genus

Species

Plant Kingdom

Flowering Plants

Non-flowering Plants

Marchantiophyta

•  Meaning: • Marchantia plants

•  Common Name: •  Liverworts

•  Characteristics: •  Ephemeral unbranched sporophytes, non-

vascular, most primitive living plant

Marchantiophyta

Bryophyta

•  MOSSES •  Dominant gametophtye

generation (green) •  Also includes liverworts and

hornworts •  Need sperm to fertilize egg •  NO vascular tissue limits

height of the plant and therefore have no true roots, stems, or leaves.

•  haploid spores are made by meiosis in the sporangium of the sporophyte.

Moss sporophyte

Anthocerophyta

•  Meaning: •  horn plants

•  Common Name: •  Hornworts

•  Characteristics: •  Horn-shaped sporophytes, non-vascular

Anthocerophyta

Lycopodiophyta

•  Meaning: • Wolf foot plants

•  Common Name: •  Clubmosses and Spikemosses

•  Characteristics: • Microphyll leaves, primitive vascular system

Lycopodiophyta

Psilophyta

•  Meaning: • Whisk ferns

•  Common Name: • Whick ferns

•  Characteristics: •  No leaves, no roots, primitive vascular

system.

Psilophyta

Sphenophyta

•  Meaning: •  Horse tails

•  Common Name: •  Horse tails, scouring rush, snake grass

•  Characteristics: • Microphyll leaves, spores, vascular system,

fossils were “tree-like”.

Sphenophyta

Pteridophyta

•  Meaning: •  Fern plants

•  Common Name: •  Ferns

•  Characteristics: •  Homosporous: create one spore that is bisexual. Vascular

tissue but no seeds: allows them to get taller, but limits them to shady moist areas for reproduction. Fronds: big “leaf like” arrangement. Fiddlehead: emerging sporophyte. Spore making sporangium on underside of fronds when reproducing.

Pterophyta

•  Fiddlehead •  Sporangia on

underside of frond

•  Fronds •  Bisexual

gametophyte

Spermatophytes

•  Includes flowering or seed-bearing plants.

•  The two subdivisions are…. •  Gymnosperms (naked seed) •  Angiosperms (flowering plants)

•  Gnetophytes (Ephedra) •  Cycad (Sago palm), •  Ginkgo, •  Conifer (pine, spruce, firs, cedars, sequoias, redwoods, junipers, yews, & cypress trees)

Gymnosperms- “naked seed”

Sago Palm Ginkgo Ginkgo

Gnetophyta

•  Brigham Tea •  Ephedra

Cycadophyta: The Cycads

Ginkgophyta

1.  Most common gymnosperms are Conifers

2.  Conifers have leaves called needles or scales have a reduced surface area and thick waxy coat on the needle to reduce water loss and prevents freezing.

Gymnosperms-Conifers

Sequoia

Juniper Pine

Conifer Reproduction

1.  Male cones produce pollen and the female cone produces eggs and seeds.

2.  Pollen is inefficiently transferred by the wind.

3.  Once mature, the scales on the female cone dry out and open scattering the seeds by the wind.

Pollen

Pollen Cone

Seed Cone

Seed cones vs. pollen cones

Seed cones

seeds

Pollen cones

Oldest and largest •  Redwoods (400 feet tall) Bristlecone pine (4600 years old)

Angiosperms

•  Flowering plants - Flower will develop into fruit that is used for seed dispersal via wind, water, or animal.

•  Pollination can be by wind, bird, bat, insect. •  Most advanced (recent) •  Gametophyte is reduced and within the flower. •  Most diverse: grasses to trees •  Divided into Monocots and Dicots

Non-woody Plants (Herbaceous)

Saguaro cactus Hepatica americana

Coconut palm (although palms are perennials, most lack secondary xylem growth and therefore, technically, they are not “woody plants”)

Major Plant Families

•  Family names end in -aceae •  http://www.sci.sdsu.edu/plants/

plantsystematics/Identifying_50_major_plant_families.pdf

Plant Descriptions and Dicotomous Keys

•  Phlox paniculata L. Garden Phlox. Plants erect, 6-10 dm tall or more; herbage puberulent to subglabrous; leaves 1.2-12 cm long, 0.8-5 cm wide, lanceolate to elliptic or ovate, subsessile or short-petiolate, acuminate apically; flowers numerous, borne in terminal, compound, often closely aggregated, corymbiform cymes, subsessile or short-pedicellate; calyx 6-9 mm long, the lance-linear lobes not spinulose, glabrous or puberulent; pink, lavender, blue, or white; stamens included; 2n=14. Cultivated ornamentals, long persisting, in lower elevation portions of Utah; introduced from the Eastern U.S.