MORPHOLOGY OF FLOWERING PLANTS

MORPHOLOGY OF FLOWERING PLANTS

Typical plant

Morphology: Study of the external appearance of an organism is called morphology.

Hydrophytes: Plants growing in aquatic habitat is called hydrophytes e.g. Hydrilla.

Xerophytes: Plants growing in regions with scanty or no rainfall like the desert is called xerophytes e.g. Opuntia.

Psammophytes: Plants growing in sandy soil are called psammophytes e.g. Elymus

Lithophytes: Plants growing on rock  e.g Couchidium

Halophytes: Plants growing in saline soil are called halophytes e.g. Mangroove plants like Rhizophora

Vegetative structure: Root stem and leaves represents the vegetative structure of the plant.

Reproductive structure: Flowers fruits and seeds represent the reproductive structure of plant.

Root: Root is descending axis of plant body which is positively geotropic and hydrotropic but negatively phototropic and aerotropic.

Root cap: A parenchymatous multicellular structure in the form of a cap, present over young growing root apex is known as root cap.

Root pockets: In hydrophytes root caps are replaced by root pocket e.g.  Pistia, Eichhornia etc.

Meristematic region: The apex of the root is a growing point about 1 mm in length protected by a root cap. This region is called a meristematic region.

Tap root: The root which develops from the radicle of an embryo during seed germination is known as tap root.

Primary root: The main root which grows vertically downward is called primary root.

Secondary root: The branches of primary root is called secondary root.

Adventitious root: The root which develops from any part of the plant except radicle is known as adventitious root.

Metamorphosed root: When roots have to perform some special function in addition to or instead of their normal function, they develop some structural changes. Such roots are called metamorphosed roots.

Fusiform root: The fusiform root is swollen in the middle and tapering towards both ends forming a spindle-shaped structure called fusiform root. e.g. Radish (Raphanus sativus).

Conical root: The conical root is broad at its morphological base and narrows down towards its apex is called a conical root e.g. Carrot (Daucus carota).

Napiform root: In the napiform root, the base of the root is highly swollen, almost spherical in shape and abruptly tapers towards its apex is called napiform root. e.g. Beet (Beta vulgaris).

Pneumatophores/Respiratory Roots: Pneumatophores or Respiratory Roots are the breathing root present in halophytes which is positively phototropic and aerotropic but negatively hydrotropic and geotropic.

Simple tuberous root: Simple tuberous roots become swollen and do not show definite shape. They are produced singly. The roots arise from nodes over the stem and penetrate into the soil. E.g. sweet potato or shakharkand (Ipomoea batatas).

Fasciculated tuberous root: A cluster of roots arising from one point which becomes thick and fleshy due to storage of food is known as fasciculated tuberous root. e.g. Dahlia, Asparagus.

Moniliform root or beaded roots: These roots show swellings at regular intervals like beads of a necklace. e.g. Spinacia oleracea (Indian Spinach).

Nodulose root: The cluster of long slender roots become enlarged at the tips forming nodules is known as nodulose roots. E.g. Arrow (Maranta root) Amhaldi (Curcuma amada).

Prop root: In trees like Banyan tree( Ficus benghalensis) roots arises from horizontal branches and grow vertically downwards till they penetrate the soil. These roots show secondary growth, become pillar-like to provide mechanical strength.

Still roots:  The aerial adventitious roots that develop from the lower nodes or the basal parts of the stem to give additional support are called stilt roots e.g members of Poaceae, like Maize, sugarcane, jowar, screwpine (pandanus).

Climbing roots: Climber plants with weak stem develop root at the nodes by means of which they attach to support e.g Betel leaf or pan Black pepper.

Clinging roots: These tiny roots develop along internodes, show disc at tips, which exude sticky substance. This substance enables the plant to get attached to walls of buildings. They do not damage substratum. e.g. English Ivy (Hedera helix).

Plank root/ Butteresses: These roots often develop at the base of large trees to form plank-like extensions around the stem is called plank root. e.g. Silk cotton, Peepal etc.

Buoyant root: Roots developed at the nodes of aquatic herbs like (Jussiaea repens), become highly inflated and spongy providing buoyancy and helping the plant to float.

Epiphyte: Plants which grow on the other plants for shelter and light are called epiphytes.

Haustoria: These are special adventitious root (Haustoria) that are modified to absorb minerals and organic matter from vascular tissues of the host are called parasite root e.g Rafflesia, Cuscuta reflexa or dodder.

Partial parasite: It absorbs only water from the host body. They are autotrophs they are in contact with the only xylem of root or xylem of the stem. e.g Striga(Partial root parasite) Viscum album (Partial stem parasite).

Complete Parasites: It absorbs both water and organic substances from the host. In this Haustoria is in contact with both xylem and phloem of the host they are heterotrophs. e.g Rafflesia.

Stem: The aerial part of the plant body is known as the shoot system. Stem is the main axis of the shoot system, It is the ascending part of the plant body which develops from plumule and reproductive units and is differentiated into nodes and internodes.

Nodes: The part of the plant stem from which one or more leaves arise, often forming some swelling are called a node.

Internodes: The portion of stem or branches between two adjacent nodes are called internodes.

Rhizome: An underground stem that is dorsoventrally flattened and grows horizontally in the soil is called a rhizome. E,g Gingers turmeric, canna etc.

Monopodial growth: In plants where rhizomes grow obliquely and  terminal bud     brings about the growth of rhizomes This is known as monopodial growth e.g Nymphea, Nelumbo

Stem tuber: Tip of underground branches becomes swollen due to storage of food material is called stem tuber e.g Potato, Matalu

Rose and heel: Tuber of potato has two distinct ends i.e apical rose end and basal heel end. The number of nodes and eyes are more towards the rose end.

Bulb: It is a modified stem consist of a relatively large, usually globe-shaped, underground buds with membraneous or fleshy overlapping leaves arising from a short stem is called the bulb.

Tunicated or Layered bulb: Tunicated or layered bulb is made up of fleshy leaves arranged in a concentric manner with outer dry scale leaf. e.g. Onion.

Scaly or non-tunicated: In garlic, the bulb is scaly or non-tunicated. The fleshy scales are arranged in an overlapping pattern.

Corm: It is swollen underground spherical or sub-spherical vertically growing stem e.g Colocasia (Arbi).

Trailer: The shoot spreads over the ground without intervals. The branches are either flat i.e. procumbent or partly vertical i.e. decumbent e.g. Euphorbia,  tridax etc

Runner: They are special narrow, prostrate or horizontal green branches which develop at the base of erect shoots known as the crown. Runners spread in all directions to produce new crowns with a bunch of adventitious roots. E.g Cynodon (Lawn grass), Centell (Hydrocotyl), Oxalis etc.

Stolon: The slender lateral branch arising from the base of the main axis is known as stolon. In some plants, it is above ground  (wild strawberry). E.g Jasmine, Mentha etc.

Suckers/Underground runner: An obliquely upward growing branches of an underground stem which when detached develop into an individual plant.

Offset: These are the aquatic runner which are one internode long runners in rosette plants at ground or Water level. The offset helps in vegetative propagation. e.g. Water hyacinth or Jal kumbhi (Eichhornia).

Thorn: Woody straight and pointed structure formed by the modification of Apical or axillary bud for defence is called thorn E.g Carrisa, Duranta, Citrus, Bougainvillaea.

Phylloclade: Modification of stem into leaf-like photosynthetic organ is known as phylloclade. e.g Opuntia

Cladode: The branch of limited growth i.e. one internode long and performing photosynthetic function are called cladodes. True leaves are reduced to spine or scales. E.g. Asparagus.

Cladophylls: These are leaf-like structures born in the axil of scale leaf. It has floral bud and scale leaf in the middle i.e. the upper half is leaf and the lower half is a stem. e.g. Ruscus

Stem tendril: Tendrils are thin, wiry, photosynthetic, leafless coiled structures. They give additional support to developing plant. Tendrils have adhesive glands for fixation.

Bulbils: Axillary bud becomes fleshy and rounded due to storage of food called bulbil. When it falls off it produces a new plant and helps in vegetative propagation.

Leaf: A leaf (plural leaves) is a (generally but not always dorsoventrally flattened) organ of a vascular plant and is the principal lateral appendage of the stem, usually borne above ground and specialized for photosynthesis. 

Leaf Primordium:  A lateral outgrowth from the apical meristem that develops into a leaf.

Hypo-podium/ leaf base: Point by which leaf remains attached to stem. It is pulvinus in Legumes.

Mesopodium/Petiole:The part of the leaf which connects leaf lamina with the leaf base is known as petiole. A leaf with petiole is a petiolate leaf.

Epipodium or Lamina: The large expanded, flat and green part of the leaf. The lamina surface plays important role in photosynthesis, gaseous exchange and transpiration.

Stipules: The small appendages present on either side of the leaf is called stipules and are protective in natures.

Axil:  The upper angle between the leaf and the node of the stem where axillary bud present is called axil.

Leaf venation: Arrangement of veins and veinlets in leaf lamina is known as venation.

Simple leaf: The leaf with entire lamina is called simple leaf.

Compound leaf: Leaf in which lamina is divided into the number of leaflets is called a compound leaf.

Pinnately compound leaf: The feather-like leaflets which are present laterally on a common axis called the rachis, which represents the midrib of the leaf is called pinnately compound leaf.

Palmately compound leaf: The leaf in which all the leaflets are attached at the tip of petiole.

Leaf spines: Sometimes the entire leaf is modified into spines (Opuntia) or margin of leaf becomes spiny (Agave) or stipule modifies into the spine (Acacia) to check the rate of transpiration or to protect the plant from grazing. E.g. Zizyphus etc.

Leaf tendril: In some weak stems for providing additional support; leaf, leaflet or another part modifies to produce a thin, green, wiry, coiled structure called as leaf tendril. It helps in climbing.

Leaf Hook: In plants like Bignonia (Cat’s nail) the terminal three leaflets get modified into three stiff curves and pointed hooks used to cling over the bark of a tree is called leaf hook.

Phyllode: When petiole of the leaf becomes flat, green and leaf-like to perform photosynthesis called phyllode.

Phyllotaxy: Arrangement of leaves on the stem and branches in a specific manner is known as phyllotaxy.

Alternates Phyllotaxy: Single leaf from each node E.g. Mango

Whorled phyllotaxy: Many leaves from each node E.g. Nerium

Opposite decussate: A pair of leaf from each node and the consecutive pair at right angle E.g. Calotropis

Opposite superposed: A pair of leaf from each node and the consecutive pair is arranged just above. E.g. Jamun

Inflorescence: A specialised axis or branch over which flowers are produced or borne in a definite manner is known inflorescence.

Racemose: In this, the younger flower produce at the apex and older flower at the base growth of the peduncle is infinite or unlimited. Apical bud is free for continuous growth. Flowers are borne in acropetal succession. Order of opening is centripetal.

Cymose: In this, the younger flower produce at the base and older at the apex growth of the peduncle is limited. Flowers are borne in basipetal succession. Order of opening is centrifugal.

Flower: The flower is highly modified and condensed shoot meant for sexual reproduction.

pedicellate flower: A flower with pedicel is said to be a pedicellate flower.

Sessile: The flower without pedicel is called a sessile flower.

Bracteate: A flower which shows the presence of bract at the base of the pedicel or over the pedicel is said to be a bracteate flower.

Ebracteate A flower which does not show the presence of bract at the base of the pedicel or over the pedicel is called ebracteate flower.

Zygomorphic flowers: Flower with bilateral symmetry is called zygomorphic flower e.g. Sweet pea.

Actinomorphic flowers: Flower with radial symmetry is called actinomorphic flower e.g. Sunflower.

Complete: The flower which shows the Presence of all four floral whorls (Androecium, Gynoecium, Calyx, Corolla) are called complete flower. 

Incomplete: Absence of any one of the four floral whorl.

Perfect : Both androecium and gynoecium are present, also called  as hermaphrodite or bisexual flower.

Imperfect : Any one reproductive whorl is present also called as monophrodite or unisexual flower.

Unisexual : It can be either staminate (male)/ pistillate (female) flower.

Neuter: When both reproductive whorls are absent, it is said to be neuter Flower. e.g. Ray floret of sunflower.

Monoecious plant: Male and female reproductive flowers are borne on the same plant. E.g. Maize.

Insertion of floral whorl: The position and arrangement of rest of the floral whorls with respect to the gynoecium on the thalamus is known as the insertion of floral whorls.

Hypogyny: When ovary occupies the highest position while other floral parts are present below ovary. The ovary is said to be superior and the flower is called a hypogynous flower. E.g. Brinjal, Mustard, China rose etc.

Perigyny: When cup-shaped or saucer-shaped thalamus is present in a flower, ovary and other floral parts occupy about the same position. Such an ovary is said to be semi- superior or semi-inferior. All floral whorls are at the rim of the thalamus. The flower is perigynous e.g. Rose, Pea, Bean, etc.

Epigyny: When ovary occupies the lower position while other floral parts are present above the ovary. The ovary is said to be inferior and the flower is called an epigynous flower, e.g. Sunflower, Guava etc.

Calyx: An outermost floral whorl of the flower which is usually green in colour and performs photosynthesis is called a calyx.

Sepal: Individual members of the calyx is called sepal.

Gamosepalous: All sepals are united e.g China rose.

Polypetalous: All sepals are free e.g Brassica

Pappus: Hairy modification of sepal e.g Sonchus

Corolla: Second floral whorl from the outer side these are coloured hence attract pollinators. 

petal: The Individual members of the corolla is called a petal.

Polypetalous: Petals are free e.g Rose

Gamopetalous: Petals are fused e.g Datura

Perianth: When calyx and corolla remain undifferentiated in a flower then it is called perianth.

tepal: The Individual members of the perianth is called a tepal.

Polyphyllous: If all the tepals are free from each other then the condition is called as polyphyllous.

Gamophyllous: If all the tepals are fused together then the condition is called as gamophyllous.

Aestivation: The mode of arrangement of sepals, petals or tepals in a flower is called aestivation.

Valvate: Margins of sepals or petals remain either in contact or lie close to each other but do not overlap are called valvate aestivation. e.g. Calyx of  Datura, Calotropis.

Twisted: One margin of each sepal or petal are directed inwards and are overlapped while the other margin is directed outwards and overlap the margin of adjacent is called twisted aestivation. e.g. Corolla of China rose, Cotton etc.

Imbricate : One of the sepal or petal is internal and is overlapped at both the margins. while one is external i.e. completely outside. Rest of the members Overlap and get overlapped. e.g. Cassia, Bauhinia, etc.

Vexillary: Corolla is butterfly-shaped and consists of five petals. Outermost and largest is known as standard or vexillum, two lateral petals are wings and two smaller fused forming a boat-shaped structure called keel or carina. e.g Pisum sativum.

Androecium: The androecium is the male reproductive part of a flower.

Stamen: The Individual member of the androecium is called a stamen.

Polyandrous: If all the stamens are free then the condition is polyandrous.

Synandrous: When stamens are fused by both filaments and anthers e.g. Cucurbita

Anther: The terminal part of stamen which produced pollen grains. It is bithecous (2 lobes) in Dature and monothecous (single lobe) in Hibiscus.

Filaments: The stalk of a stamen is called a filament.

Connective: The structure which connects two another lobes together and also with the filament is called connective.

Adelphy: When stamens are united by filaments and anthers are free, the condition is called adelphy.

Syngeny: When anthers are united and filaments are free it is known as syngeny. e.g. Sunflower.

Epipetalous: When the stamens are united to petals or tepals then they are called as epipetalous e.g. Datura, Lily etc.

Gynoecium: Female reproductive part of the flower is called gynoecium. It is also called Pistil and unit is called carpel.

carpel: The Individual member of the gynoecium is called a carpel.

Syncarpous: When all the carpels are fuse together then the condition is called syncarpous. 

Apocarpous: When all the carpels are free from each other then the condition is called syncarpous. 

Stigma: The terminal part of carpel which receives pollen grain or the expanded tip of the style is called stigma.

Style: It is a narrow thread-like structure which connects the stigma to the ovary is called style.

Ovary: The basal swollen fertile part of the carpel is called the ovary. 

Ovule: Ovary containing body is called an ovule.

placenta: The soft fertile a tissue through which an ovule attach to the ovary is called the placenta.

Placentation: The mode of arrangement of ovules on the placenta within the ovary is placentation.

Marginal: Ovules are placed on the fused margins of the unilocular ovary. e.g. Pea, Bean etc

Axile placentation: Ovules are placed on the central axis of a multilocular ovary. e.g. China rose, Cotton; etc

Parietal Placentation: Ovules are placed on the inner wall of the unilocular ovary of multicarpellary syncarpous gynoecium. e.g. Papaya, Cucumber.

Basal Placentation: Single ovule is present at the base of the unilocular inferior ovary. e.g. Sunflower, Rice, Wheat.

Free central: Ovules are borne on a central axis which is not attached to the ovary wall. e.g. Fig

Fruit: In angiosperms after the fertilization the ovary enlarges to form fruit.

Parthenocarpic fruits: Sometimes fruit is produced from ovary without fertilization. Such types of fruits are called as parthenocarpic fruits and phenomenon is called parthenocarpy. E.g Banana, Grapes.

True fruits/Eucarp: The fruit which develops from the ovary only is called true fruit or eucarp. e.g. Mango.

Pseudocarp: The fruit which develops from the ovary and any other floral part is called false fruit of pseudocarp. e.g. Apple.

Pericarp: The wall of fruit is called pericarp. It is divided into outer epicarp, middle mesocarp and inner endocarp.

Simple fruits: When Fruit develop from one ovary of one flower is called simple fruit.

Dry fruits: Fruits with a thin pericarp is called dry fruits.

Fleshy fruits: Fruits with thick pericarp is called fleshy fruits.

Dehiscent: The type of dry fruits whose fruit wall breaks at maturity to release seeds are called dehiscent e.g Capsule of Lady finger & legume of a pea.

Indehiscent : The type of fruit whose fruit wall do not break at maturity known as dry indehiscent fruit e.g Achene of mirabilis, caryopsis of maize, cypsela of Sunflowers.

Aggregate fruits: Many ovaries of apocarpous gynoecium can form one fruit. Such fruits are called aggregate fruits. Aggregate fruits are a collection (Etario) of many varieties. They can be etario of achenes (Strawberry), etario of berries (Custard apple), etario of follicles (Calotropis).

Composite fruits: Many ovaries of many flowers but of one inflorescence from one fruit. Such fruits are called composite fruits.

Syconus: The one which develops from hypanthodium (floral axis being fleshy and closed forming a pear-shaped receptacle) inflorescence is syconus e.g. Fig.

Sorosis: Sorosis (Pineapple) develops from Catkin ( a slim, cylindrical flower cluster, a spike, with inconspicuous or no petals) inflorescence.

Seed: A reproductive unit that developed from the fertilized mature ovule.

Seed coat: Outermost covering of a seed is called the seed coat shows outer layers called testa and inner tegmen.

Hilum: The hilum is a scar on the seed coat through which seed attaches to the fruit.

Tigellum: Embryonal axis between Radicle and plumule.

Epicotyl: Embryonal axis between cotyledon and plumule.

Hypocotyl: The part between cotyledon and radicle is hypocotyl.

Endosperm: The triploid (3n) nutritive tissue in a seed called endosperm.