Plant Morphology, Classification, and Nomenclature

Plant Materials 1

plant morphology

the study of the physical form and external structure of plants

What is important for the visual identification of plants?

plant morphology

Plant morphology includes what two structures?

vegetative and reproductive (varied and specific to a particular plant group)

Vegetative structures include what systems?

shoot (stems and leaves) and root

What groups are plants placed into based off of how they reproduce?

Angiosperms (flowers and fruits)

Gymnosperms (“naked seeds” like conifers and gingko (seed cones))

Ferns (sori)

What groups of plants are considered seed-bearing plants?

angiosperms (flowering like oak, maple, rice, potato, water lilies, apple, tomato, and Chinese lantern)

gymnosperms (no flowers)

What group of plants is considered spore-bearing? (reproduce by spores)

ferns and fern allies

What are the parts of a leaf?

bud, petiole, and blade

Are all the leaves on a tree the exact same size, appearance, color, or even shape?

No

What kind of leaves do angiosperms have?

broad with a wide blade

can be simple or compound

What kind of leaves do gymnosperms have?

narrow and slender without a wide blade

can be awl, scale, or needle

simple leaves

have only one leaf blade, with or without a stalk or petiole

compound leaves

have more than one blade and may have a complex leaf stalk structure

pinnate (also bipinnate and tripinnate)

a compound leaf that has a number of leaflets attached along a central stalk

palmate (trifoliate)

a compound leaf that has three or more leaflets attached at the end of the stalk (petiole) - like fingers on hands

____ have a bud at the base of the stalk (petiole), but ___ do not

leaves, leaflets

something about petioles and enclosed buds

something about petioles and enclosed buds

What type of narrow leaf is depicted?

awl (norfolk island pine)

What type of narrow leaf is depicted?

scale (cypress)

What type of narrow leaf is depicted?

needle (pine)

What are the types of leaf arrangement?

opposite, alternate, whorled

opposite leaf arrangement

two leaves being attached at the same location (a node) on a stem, but opposite each other

alternate leaf arrangement

a single leaf attached at one location (a node) on a stem

whorled leaf arrangement

more than two leaves arise from the same location (a node) on a twig

Can a plant exhibit more than one single type of leaf arrangement?

yes

Types of leaf characteristics:

lobed (or not) and type of margin

overall shape

shape of base

shape of apex

pattern of venation

surface properties

odor when crushed

Types of margins on leaves:

entire (smooth)

toothed (coarsely, double, or serrate (single, double, spiny))

dentate

lobed leaf vs. leaf without lobe (image)

toothed leaf margin

may occur at the base of a leaf, at the tip, or along the whole margin

may vary in number and size (coarsely or doubly)

serrated leaf margin

saw toothed, teeth pointing forward

single, double or spiny

dentate leaf margin

having marginal teeth whose apices are perpendicular to the margin and do not point forward

pith (stem)

core of the stem of most plants

lenticels (stem)

porous tissue, allows gas exchange between the atmosphere and tissue of plant

morphology of buds

scaly or covered scales (modified leaves cover and protect embryonic parts)

naked (not covered by scales)

hairy (protected by hairs, may apply to either scale or naked)

What are the functions of buds?

vegetative (leaf, embryonic shoot with leaves)

reproductive (flower, embryonic flowers)

mixed (both embryonic leaves and flowers)

What is the location of buds?

terminal (tip of a stem)

axillary (axil of a leaf)

adventitious (occurring elsewhere, on trunk or roots)

Head inflorescence, inner disk flowers usually fertile, outer ray flowers usually ___

sterile

fused staminate column

stamens fused around the style of the pistil

____ borne above the ovary; this structure retained as fruit

perianth

fruits

type, shape, color

simple (dry(nuts), fleshy (avocado))

aggregate (single flower, many carpels)

multiple (multiple single-carpel flowers (multiple drupelets))