Topic 2 - The morphology and main modifications of vegetative organs

Question 1

Major benefit of plant morphology

Answer 1

Helps to study and identify plants

Genera and families have typical compounds

Explanations for non-studied plant poisonoings

Question 2

Major parts of plants

Answer 2

Root 
Bud
Shoot 
    *  Stem 
    **      Node
     **     Internode 
     *  Leaves 
Flower 
Inflorescence
Fruit 
       *  Seed

Question 3

Major functions of the root system

Answer 3

Anchorage
Uptake of water and minerals
Transport
Storage (photosynthesis)

Question 4

types of roots

Answer 4

True roots (from radicula)
Adventitous roots
Modified roots

• Interspecific
• Aerial

Question 5

True roots

Answer 5

Develop from Embryonic root

tap root
branch roots

Question 6

Adventitious roots

Answer 6

(for organs other than roots)
Fibrous root system
Roots arise on nodes, cut surfaces controlled by hormones

Question 7

Modified roots

Answer 7

Storage roots
o	Used as fleshy forages
o	Mainly sources of carbohydrates
o	Less amount of thickened cell walls  better digestibility
o	Storage taproot—>carrot
Root tubers —> tuberous pea
Beetroot —> sugar beet, radish
o	Fusion of root and stem parts

Question 8

Interspecific modifications

Answer 8

Nutrient transport between species
Either benefits and harmful effects

Mycorrizal roots
Root nodules
Haustorium

Question 9

Mycorrizal roots

Answer 9

plant roots associated with beneficial fungus

o	Ecto: trees and mushrooms
o	Endo (arbuscular): present for 85-90% of angiosperms
o	Better phosphorus uptake
o	Better resistance
o	Better assimilation rate

Question 10

Root nodules

Answer 10

symbiotic interaction between roots and bacteria

o Mainly rhizobium species
o Fabaceae family
o Better nitrogen fixation
o Higher protein level

Question 11

Haustorium

Answer 11

A structure that grows into or around another structure to absorb water or nutrients

Parasitic and semiparasitic plants

Dodder (Cuscuta) species which can infect crop plants

Low production, phytobezoars

Question 12

Aerial roots

Answer 12

Specific for genera or species

• Formed by above ground structures (stem)

Question 13

Buds

Answer 13

Bud (gemma) = embryonic shoot

Vegetative bud of biennial species → forage
Food for game species → ← game damage

Question 14

Types of buds

Answer 14

vegetative, reproductive, mixed

Question 15

Function of buds

Answer 15

protection of shoot apex = bud scales

Question 16

Function of the shoot system

Answer 16

Strengthening
Support leaves and flowers 
Transport
Photosynthesis
Storage

Question 17

Types of shoots (stems)

Answer 17

Woody

Herbaceous

Question 18

Woody stems

Answer 18

Lignification → deposits of lignin in cell walls → decreasing digestibility

Woody stem (secondary growth → increase in thickness of plant)
o Trees
o Shrubs
o Subshrubs

Palm tree (no secondary growth, fused leaf sheats)

Question 19

Herbaceous stems

Answer 19

Lignification is possible in older organs

Determine forage value

Common dicot stem – with lateral branches and non-conspicuous nodes
Grass stem – in Poaceae family, hollow internodes, thick nodes, no lateral branches
Rosette – circular arrangement of leaves, short internodes
Sedge stem – for certain species of sour grasses (e.g. sedges), short internodes close to the ground, spongy inner parts low feeding value

Question 20

Major types of modified stem above grounds

Answer 20

Stem tendril (cyrrus): simple (cucumber) or branched (pumpkin) – climbing

Thorns (spina)
simple (firethorn) or
branched (honey locust) – protection

Runner (sarmentum): elongated internodes (strawberry) vegetative reproduction

Succulent stem: cylindrical or spherical – water storage

Phylloclades: leaf-like stem – assimilation (butcher’s-broom)

Question 21

Major types of modified stems below ground

Answer 21

Generally store starch (or other carbohydrates)

Rhizome (rhizome): short internodes
Ferns, monocots (horizontal)
Dicots (vertical)
Stolon (stolo): elongated internodes – grasses

Bulb (bulbus) – for monocot species, fleshy cataphylls dry bracts

Tuber (tuber) – thickened stem, storage function, forage importance

Bulbotuber – intermediate form (meadow saffron)

Question 22

Leaf

Answer 22

Phylum, folia

Vegetative organ with determined growth

Question 23

Functions of the leaf

Answer 23

Photosynthesis, storage

Question 24

Major leaf types

Answer 24

Cotyledon
Cataphylls
Hypsophylls

Question 25

Cotyledon leafs

Answer 25

= seed leaf, embryonic leaf
Remains in the soil - nutrient storage
Emerges above ground - photosynthesis
Number: many (gymnosperms) 2, 1, 
Important source of nutrients

Question 26

Cataphylls

Answer 26

Scales on underground stems that function in protection and storage

Question 27

Hypsophylls

Answer 27

Mainly floral bracts, function in protection or pollinator attractants —> highly specific

Question 28

Foliage leaves

Answer 28

The leaf base connects to the stem
Grasses —> leaf sheath
Stipules can be present on both sides
Petiole (leaf stalk) —> holds the leaf blade, but it can be absent (sessile leaf)
Leaf blade —> gas exchange, photosynthesis

Question 29

Division of the blades of foliage leaves

Answer 29

Undivided

Divided
Palmately
Pinnately

Question 30

Depth of divisions of foliage leaves

Answer 30

Lobed
Cleft
Parted
Dividied

Question 31

Heterophylly

Answer 31

Having dissimilar leaves on one plant

Ref. foliage leaves

Question 32

Leaf margins of foliage leaves

Answer 32

Entire
Dentate
Serrate
Crenate
Sinuate

Question 33

Compound leaves

Answer 33

Single leaves
The blade divided into leaflets
     Palmately 
     Pinnately 
           Paripinnately (odd-pinnate)
           Imparipinnate (even-pinnate)
     Bipinnate leaves: leaflets also pinnate

Question 34

Venations (function)

Answer 34

Transport water and nutrients

Strengthening

Question 35

Types of venations

Answer 35

Dichotomous
Parallel (monocots)
Netted or reticulate (dicots)
Pinnate, palmate

Question 36

Phyllotaxis

Answer 36

Arrangement of leaves on the stem
Spiral: one leaf per node
Opposite: two leaves per node
Whorled: more than three leaves per node

Question 37

Important leaf modifications

Answer 37

Leaf tendrils
Spines
Succulent leaves