Horticulture - Exam 2 Jackson NCSU

Functions of Stems

Storage, transportation, support, food, bears flowers and fruits

stem parts

nodes, internodes, and buds

nodes

place on stem where buds/leaves are formed

internodes

space on stem between nodes

buds

undeveloped shoot or flower

Bud/Leaf Arrangment

alternate, opposite, or whorled

alternate arrangement

one bud/leaf per node

opposite arrangement

two buds/leaves per node

whorled arrangement

three or more buds/leaves per node

prostrate stem

stems that run along the ground

stolon

prostrate stem that runs along the ground and produces a plantlet at tip. ex. strawberry, spider plant

Rhizome

prostrate stem that runs below ground and produces plantlet at tip ex. bamboo, Bermuda grass

Irish potato

modified stem called a Tuber

Sweet potato

modified root called tuberous root

leaf parts

petiole, blade, stipule

petiole

stalk of a leaf

blade

brand expanded part of a leaf

stipule

small leaf-like appendage at bone of leaf

how to look for a leaf?

look for the BUD

simple leaf type

uninterrupted leaf blade

compound leaf type

interrupted/divided leaf blade

poison ivy

deciduous vine with alternate leaves, compound, uses adventitious roots

Danae racemosa

poets laurel

cladophylls

leaf like structures that are truly modified stems

example of cladophylls

Christmas cactus

Epidermis

regulates the loss of gases, regulates the loss of water, and protects the internal constituents

specialized epidermal cells

guard cells (stomata), they regulate water loss and release carbon dioxide

cuticle

waxy coating, seals cracks between epidermal cells, regulates gas loss, regulates water loss

trichomes

hairs

palisade layer

under the epidermis; contains tightly packed chloroplasts - site of photosynthesis

spongy mesophyll

between palisade and lower epidermal later; loosely packed cells with air space between (water vapor, oxygen, CD)

what are the four classic flower parts

petal, sepals, pistil, and stamen

petal

(corolla) - pigmented structures to attract pollinators

sepals

(calyx) - protective covering during bud stage (before flowers open)

pistil

female reproductive organ

stamen

male reproductive organ

What part of corn is the staminate organ?

the tassels

what part of corn is the pistillate organ?

the silks

bract

a leaf -like structure at the base of a flower sometimes pigmented ex. dogwood, poinsettia

complete

flowers with all four class parts are called :

incomplete

flowers missing one or more of the four parts are called :

perfect

flowers which have both sexual parts are called :

imperfect

flowers missing a sexual part are called :

monoecious

pistillate and staminate flowers separated but on SAME plant

dioecious

pistillate and staminate flowers separated on DIFFERENT plants

emasculation

removal of anthers

single/solitary

one flower borne per stem

inflorescence

many flowers grouped together on one stem

pollination

pollen aligns on the stigma and is accepted

fertilization

male genetic information fusses with an egg in the ovary

false

pollination ensures fruit production - true or false

true

fertilization is the result of pollination - true or false

pollen tubes

grown from a grain to touch the ovule so fertilization can commence

aids in pollination

wind, mammals, insects, birds, water, people

Eyespots

small darker coloring near the opening of a flower

amorphophallus titanum

the death flower, 12 degrees temperature increase between inside and outside

self compatible

plants accept their own pollen, but they will also accept "foreign" pollen

self incompatible

plants that will ONLY accept "foreign" pollen

ways to overcome incompatibility in fruit orchards

plant pollinator rows, grafting

what is a fruit?

a mature flower ovary that houses the product of sexual reproduction

fruit morphology

the makeup of ovary tissue

gymnosperms do not produce ovaries, only ...

angiosperms do

pericarp

outer wall of fruit

exocarp

outer most layer of pericarp (skin)

mesocarp

middle layer of pericarp (flesh)

endocarp

inside layer of pericarp (around seeds)

simple fruits

developed from a single flower with one pistil and simple or compound ovary

berry

fleshy fruit, edible pericarp

pepo

berry-like with thick or leathery exocarp, fleshly mesocarp, and watery endocarp

hesperidium

rindy exocarp, pulpy mesocarp, papery endocarp

drupe

thin exocarp (skin), fleshy mesocarp, and "stoney" endocarp

Pome

exocarp skin, mesocarp fleshy, endocarp; leathering case around seed

multiple fruit

fruit formed by several flowers being fused during ripening

aggregate fruit

fruit formed by several ovaries within one flower

dry fruit types

dehiscent and indehiscent

dehiscent

pericarp splits along seam when ripe

indehiscent

pericarp does not split when ripe

what is a seed?

miniature plant surrounded by protective covering called a seed coat... a plant embryo.

seed viability

the ability of a seed to germinate and grow normally

seed longevity

how long a seed remains viable

what factors influence seed longevity?

species, time, stage conditions

what is required for successful germination?

must be ripe, viable, temperate seeds must not be dormant, warmth, media, moisture, and light.

two types of dormancy

-Physical (seed coat)

-Physiological (biochemical)

physical dormancy

structural conditions such as freezing, thawing, rain, natural weather, birds and animals, and from scarification from humans

scarification

process where the seed coat is compromised so water can enter and stimulate germination

there are three main types of scarification

mechanical, hot water treatment, sulfuric acid dunk

physiological dormancy

exposure to differing temps and moisture regimes, warm/dry, cold/moist, warm/moist

stratification

process where seeds are exposed to the following environments; 60-90 days in moist media, at a temp of 45 or below, placed in growing conditions

what is double dormancy?

when a seed is both physically dormant and physiologically dormant

plant growth

increase in size/mass (quantitative)

plant development

differentiation of cells and tissues; does not have to increase in size or weight (qualitative)

cellulose

principle polysaccharide in cell walls

another name for cellulose?

dietary fiber

meristem

zone of actively dividing plant cells

types of meristem

primary and secondary

primary meristem

found in shoot tips and root tips, produce primary tissues which contribute to primary growth.

secondary meristem

cells responsible for lateral growth (i.e. girth) and found in the vascular cambium, cork cambium, intercalary meristems

Xylem

transports water up

phloem

transports sugar down

pith

soft tissue in center of stem/root