Plant morphology as a division of Botany.

Lecture 5 MORPHOLOGY OF VEGETATIVE ORGANS OF PLANTS • Plant morphology as a division of Botany. • Definition of vegetative organs. Application of vegetative organ morphology in macroscopic analysis of plant raw material. • Root: definition of an organ. Types of roots and root systems. • Specialized roots. • Shoot: functions and main morphological characteristics. • Specialized shoots: above- and underground. • Leaf: morphological definition. Parts of leaf and their functions. Types of leaves and venation. Author: As.-prof. Shanayda M.I.

Plant morphologyis the second division of Botany which studies of external structure of plants. Plant morphology observes the vegetative (somatic) and reproductive structures of plants.

Ginseng Sweet flag Plantain Vegetative organs are widely used in medicine (roots, stems, herbs, buds and leaves and their modifications)

ROOT Root (lat. radix) is the vegetative organ of a plant body. It has radial symmetry and positive geotropism. It is also a part of a plant body that bears no leaves and nodes. The two major functions of roots are: 1)Absorption of water and inorganic nutrients, 2) Anchoring the plant body to the ground. Sometimes roots have also other functions…

Types of roots according to origin: 1) Primary root develops from seed embryo, 2) Lateral roots develops from primary root, 3) Additional (adventitious) roots grow from stem or leaf.

A root system consists of different types of roots. • The taproot system is most common in • Dicotyledonous plants (dandelion, sunflower and trees). • 2) The diffuse root system (fibrous root system) • is most common in Monocots plants (wheat, corn) • and plantain

Specialized roots The roots, or parts of roots, of many plant species have become specialized to serve adaptive purposes. Tap-roots Tuberous roots of sweet potato (Ipomoea batatas) and yam (Dioscorea) and cassava (manioc)

Tenacity roots Haustorial roots Aerial roots

Breath roots (or pneumatophores) Stilt roots(orprop roots)

Mycorrhizasare symbiosis with fungi (mushrooms). Bacteriorhizas Root nodules occur on the roots of plants (primarily Fabaceae) that associate with symbiotic nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known as rhizobia. are symbiosis with bacteria (beans, clover from Legume family).

Contractile rootformed in onions and contract bulb to the ground

Economic importance of roots. Sugar-beet is an important source of sugar. Cassava (manioc) is extensively cultivated in tropical and subtropical regions for its edible starchy tuberous root, a major source of carbohydrates. The flour made of the roots is called tapioca. Carrot, horseradish and sweet potato wew use as food. Important medicines from roots are ginseng, gentian and liquorice. Important medicines from roots are ginseng, gentian, and liquorice

SHOOT SHOOT (lat. cormus) is the vegetative organ of plants, that includes the stem, leaf and bud, also node and internode.Stem is an axial organ of plants, the part of shoot.Leaf is a lateral organ of plants, the part of shoot.Nodeis a point on the stem where leaf or bud is born. The space between two nodes is an internode.

BUD(lat. gemma) is a compressed, undeveloped shoot. Buds may be lateral (axillary and adventives) or terminal, vegetative (cabbage) and generative (tulip).

The buds of birch, poplar and other plants are used in medicine.

STEM is an axial organ of plants • The shape of stem • in cross-section can be: • cylindrical (wheat, oak), • triangular (sedge), • square (peppermint), • ribbed (cactus) The types of stems according to position in the space are divided into: straight (trees, wheat), creeping (strawberries), recumbent (bird-knotgrass), climbing (hop-plant), clinging or tenacious (ivy-plant)

A BRANCH is a woody lateral stems of trees and shrubsThe bark (lat. cortex) of branch of oak, snow-ball, willow tree branches are used in medicine. branch bark

Types of stem branching can be: monopodial (spruce-tree) sympodial (bird cherry) dichotomic (club moss, brown algae fucus) pseudosympodial (lilac)

1. Underground SHOOT MODIFICATIONS: Tuber Bulb Corm Rhizome

2. Abovegraund SHOOT MODIFICATIONS: Tendrils Stolons Spines Thorns Aerial bulb Phyllodium Tendrilscoil around objects and help support the plant (grape-vine, peas).

Thornsare modified stems (hawthorn,sea Buckthorn).

Spinesare modified leaves (cactus,barberry) or stipules (acacia) .

Stolonsare the moustache of strawberry Phyllodium- the flat extended petioles of sheet (Australian acacias) Aerial bulbformed in inflorescens of garlic, lily

Economic importance of shoots.White and green asparagus crispy stems are the edible parts of this vegetable. The stems of bamboo or kohlrabi are used as vegetables. Sugar-cane stems are a major source of sugar

Parts of shoot are often specialized for asexual (vegetative) reproduction

LEAF (lat. folium) Leaf is the most active and conspicuous organ of plants. Part of leaf are: Petiole is the stalk of a leaf; a leaf without a petiole is sessile (grass).Bladeis the flat, expanded portion of the leaf. Stipules are flat leaf-like flaps below a leaf. Not all leaves have stipules.

Simple and compound leaves Simpleleaves are the leaves in which the blade is all in one piece, though it may be lobed and dissected. Compoundleaves are the leaves in which the blade divided all the way to the midrib into 3 or more pieces.

Shapes of blade 1) Acicularis a needle-like leaf (pine), 2) Cordateis aheart-shaped leaf with the wide part at the bottom (lime-tree), 3) Falcate leaf formed like falcate (eucaliptus), 4) Linear is avery long and thin leaf with the paralleled sides (grass-like), 5) Ovateis anegg-shaped leaf (plantain) 6) Sagitate is a leaf of horse sorrel.

Leaf margins There is an astounding number of terms used to describe the margin of a leaf. The most common are: Dentateis a leaf with teeth pointed outwards (buttercup). Entire is a smooth leaf with no teeth or lobes (lilac), Serrate is a leaf with sharp, forward-pointing teeth (nettle),

Basic types of multipartite blade of simple leaf are: a) lobed (oak); b) separated (larkspur, fig, matherwort), c) dissected (potato, Monk's-hood).

COMPOUND LEAVES have the blade that are divided all the way to the midrib into 3 or more pieces. The most common are: Pinnately compound leaves have leaflets arranged along one undivided main axis (rose,rowan-tree). Palmately compoundleaves have leaflets all arising from one point at the base of the leaf (horse chestnut) Three-leaves compound leaves have three leaflets (clover, strawberry)

TYPES OF LEAVES VENATION Parallel (grass). Arc-parallel (lily of the valley). Palmate (maple). Pinnate (ouk, cherry). Dichotomous (Ginkgo)

ARRANGEMENT LEAVES ON THE STEM. There are 4 types of leaf placement: Alternate (willow, oak). Opposite (pepermint, maple). Whorled (oleander). Rosulate (dandelion, parsley,plantain).

Life duration of leaves Evergreen plantshave leaves which persist for two or more seasons. Evergreen plants usually have thick, leathery leaves (pine-tree, spruce-tree). Deciduous plants have leaves which die and fall in the cold or the dry season every year (95 % of plants are deciduous)

GROWTH FORM OF PLANTS Treeshave woody, usually one main stem and the hight more than 25m tall (oak-tree, apple-tree). Shrubs have woody, several stems from the base, less than about 20 m tall (snowball-tree). Hemishrubs have woody and herbaceous several stems, less than about 2 m tall (lavender, wormwood). Vines have woody or herbaceous, stem climbing or tenacious (grape-vine). Herbs have no woody tissues. They are divided into:

DURATION life of herb Annual (camomile, beans), Biennial (carrot, sugar-beet), Perennial(dandelion, tulip).

Plant morphology as a division of Botany.