PLANT ANATOMY
Term coined by A.P. de Candolle
Components of taxonomy: Classification, Nomenclature and Identification
Some plant families
Graminaeae (Poaceae)
Grass family
Inflorescence: Spike/panicle/spikelets
Leaves: alternate, distichous with
sheathing base
Glumes: modification of bract
Perianth represented by scales/lodicules
Anthers: versatile
Stamens: 3. distinct and with pendulous
Fruit: Caryopsis
Examples
Rice (Oryza sativa)
Sugarcane (Saccharum officinarum)
Maize (Zea mays)
Wheat (Triticum aestivum)
Oat (Avena sativa)
Bamboo
Solanaceae (Potato family)
Bicarpellary vascular bundle in stem
Inflorescence: Solitary, umbellate cyme or helicoid, axillary,
Ovary: superior obliquely placed
Axile placentation
Fruit: Berry, Capsule
Examples
Potato (Solanum tuberosum)
Tomato (Lycopersicum)
Solanum nigrum
Capsicum
Datura stramonium
Atropa belladonna
Tobacco (Nicotiana tobacum)
Cruciferae (Brassicaceae)
Mustard family
Inflorescence: Raceme, Corymb raceme
Stamen 6, tetradynamous (2+4), 4 inner and longer
Parietal placentation
2 carpel are placed transversely
Fruit Siliqua or Silicula al
Examples:
Turnip (Brassica rapa)
Mustard (Brassica campestris)
White candytuft (Iberis amara)
Sheperd's Purse (Capsella)
Liliaceae
Lily family
Herbs and climbers rarely shrubs
Flower: actinomorphic, trimerous, bisexual, epiphyllus
Perianth leaves: 6
Stamen: 6, Carpels: 3
Fruit: Berry
Examples:
Onion (Allium cepa)
Garlic (Allium sativa)
Aloe vera
Asparagus
Colchicum
Medicinal plants
a. Opium (poppy)
Papaver somniferum
Latex from unripe capsule
Morphine, codeine are extracted from it and used for pain relieving
b. Rauwolfia serpentina
Parts used: roots
Reserpine, serpentine are extracted
from it
Reduce blood pressure and cures
schizophrenia
Increase uterine contraction
c. Digitalis purpurea
Cardiac stimulant, relieving dropsy and stimulate renal secretion
d. Cinchona
Cinchona officinalis
Parts used: bark
Used as antimalarial drug
e. Colchicium luteum
Family liliaceae
Roots and seeds are used
Colchicine is obtained from it
Used for rheumatism, gout and joint pain
f. Datura stramonium
Family solanaceae
Leaves, seeds, fruits are used
Atropine, hyoscine are obtained
It is a narcotic, used in rabies, asthma, skin disorders
g. Aconitum napellus
Parts used: roots
For cholera and leprosy
h. Aloe vera
Family liliaceae bis
Parts used: leaves
Use in liver and spleen defects
Also used in skin disease, toxemia and bur
PLANT ANATOMY
Father of plant anatomy is N. Grew.
Safranin stains lignified elements deep red and Hematoxylin stains cellulose element purple.
Tissue----- termed by N. Grew.
Group of cells having a common origin and performing a common function is tissue. Promeristem is earliest stage and divide to form primary meristem.
Primary meristem
Secondary meristem is formed by de-differention of primary permanent tissue. Eg. Interfascicular cambium, cork cambium.
Apical cell theory given by C. Nageli. Applicable to higher algae, bryophytes and pteridophytes only. States single cell to be responsible for entire growth by division and redivision.
Histogen theory-----------> given by Hanstein
Dermatogen form epidermis.
Periblem form cortex including endodermis.
Pleorome forms vascular bundle including pith.
Tunica corpus theory (proposed by Schmidt) {Most accepted theory}
Tunica(outer)--- divide anticlinally for surface rowth.
Corpus(inner)--- divide anti and periclinally to produce bulk of adult plant.
Healing of wound in plant is by secondary meristem.
Intercalary meristem increases height in Bamboo, monocots, grasses.
Intercalary meristem present at
- base of internode (above node)----------->Grass
- Base of leaf------------------>Monocots and Dicots
- Base of node--------------> Mint or menthe
Shoot apex is terminal but root apex is sub terminal or sub apical because of root cap.
Apical cell theory -----------> Nageli
- Applicable to pteridophytes and gymnosperms and not to angiosperms.
Histogen concept-------->Hanstein
- Root cap formed by Calyptrogen in monocots and dermatogens in dicots.
Quiescent centre concept (Given by Clowes in maize).
Quiencent centre have low DNA, RNA and protein.
Cells are at G0 phase that replace damaged cell of meristem.
Permanent tissue (Simple permanent and complex permanent)
Simple permanent (Parenchyma, Collenchyma, Sclerenchyma)
Parenchyma------Storage function
Modifications
Prosenchyma----Parenchyma taper at both ends
Aerenchyma----In hydrophytes, help in floating
- Aerenchyma in land plants is star shaped and known as stellate parenchyma as in Banana, Canna, etc.
Chlorenchyma----Parenchyma with chlorophyll
Idioblastic parenchyma----Storage parenchyma containing enzymes, resin, ergastic substance, etc. (cell inclusions)
Collenchyma- living mechanical tissue
Not found in roots and monocots.
Form hypodermis of dicot herbaceous stem and woody climber (Lianas).
Sclerenchyma
Stained with safranin
- Sclerenchyma fibers
- Sclereids or stone cells
Sclerenchyma fibers------>Directly derived from meristematic cells.Elastic and flexible. Tapering at both ends.
Sclereids or stone cells-------> Derived from secondary thickening of parenchymal cells. Present in endocarp of coconut, hard seed coats, fruit pulp of guava, pear, etc.
Brachysclereids------->Irregular (Stone cells)
Macrosclereids-------->Rod shaped, seed cots of Leguminosae
Osteosclereids---------->Bone shaped, sub-epidermis of legume seeds
Astrosclereid--------> Star shaped, tea leaves, petiole of lotus
Complex permanent tissue
- Xylem
- Phloem
Xylem
- Termed by C. Nageli
Functional part Hadrome.(by Haberlandt)
Unidirectional movement.
Secondary xylem-Wood
Vessel
Vessel absent in leaves and stem of Yucca and Dracena.
Non-angiosperms containing vessels are some species od Selaginella and Pteridium(Equisetum, Marsilea).
Gnetum, Welwitschia and Ephedra also contain vessels.
Tracheids
Only tracheids form xylem of pteridophytes and gymnosperms. Found in all vascular plants.
Xylem cells are polygonal in dicots and oval in monocots.
Tyloses are balloon like ingrowths through pits in the lumens of vessels and tracheids which plug them.
- Exarch----protoxylem outside, metaxylem central, eg. Root of monocots and dicots
- Endarch- protoxylem central, metaxylem peripheral, eg. Stem of dicot and monocot .
- Mesarch- protoxylem surrounded by metaxylem from both sides. Eg. Fern
Protoxylem is mature than metaxylem.
Phloem
Conducting part Leptome (by Haberlandt)
Translocation of food bidirectional.
Secondary phloem--------------->Bast
Sieve tube
Sieve pores are present in contact transverse wall.
Sieve pores get plugged with callose in winter which dissolve in summer.
Sieve tube is absent in pteridophytes and gymnosperms. Instead of sieve tubes, sieve cells are present.
Companion cells
It’s nucleus regulate function of sieve tube.
Absent in phloem of pteridophyte and Gymnosperm.
Instead albuminous cell present.
Companion cells (many) are associated with one sieve tube.
Phloem parenchyma
Absent in most of the monocots and few dicots like Ranunculus.
Cavities for storage of their products
Lysigenous cavities- produced by breakdown of cell. Eg. Oil cavity of citrus and Eucalyptus.
Schizzogenous cavities- produced by separation of cells. Eg. Resin duct of Pinus, mucilage duct in Cycas.
Schizolysigenous are produced by both. Eg. Protoxylem cavity of maize stem
Secondary tissues of special tissues
- Glandular tissue
- Laticiferous tissue
Glandular tissue
Tissue which secrete essential oil are called osmophores.
Laticiferous tissue
Multinucleate i.e. Coenocytic
Latex may be watery(Banana), milky(Euphorbia, Banyan) or coloured(Opium)
Latex of banana contain tannin, latex of Papaya contain papain.
Para/Natural rubber-Hevea brasiliensis
Indian rubber- Ficus elastic
Panama rubber- Castilla elastic
Cera rubber- Manihot glaziovi
Vascular tissue system
Radial vascular bundle----------------->Roots
Bicollateral vascular bundle----------------->Cuscuta, Cucurbitaceae, Solanaceae
Monocot stem have conjoint, collateral and closed type of vascular bundle.
Concentric vascular bundle
- Amphicribal(hadrocentric)- Xylem central
- Amphivasal(leptocentric)- Phloem central
Stele- Total tissue below epidermis
Dicot- Vascular bundle in ring--------------->Eustele
Monocot----------------->Vascular bundle scattered----------------->Actatostele
Cambium absent in Monocots so no grafting.
Suberin----------------->Cork cell, casperian stripes
Bark----------------->Total tissue outside vascular cambium. (Phloem+Pericycle+Periderm)
Abnormal secondary growth----------------->Dracena, Agave, Yucca @DAY
Annual ring not distinct in tropical zone.
Dendrochronology----------------->Finding age of plant counting annual ring
Dendroclimatology----------------->Study ofclimate studing annual ring.
PLANT MORPHOLOGY
No response to gravity: Apogeotroic
Pneumatophore (Mangrove): -ve geotropic
Coralloid root (Cycas): Apogeotropic
Root→ No node and internode
Root cap forming histogen
Calyptrogen→Monocot
Dermatogen/ Protoderm→ Dicot
In hydrophytes, root pocket is present instead of root cap.
Zone of cell maturation
- Pericycle produce secondary root endogenously
- Unicellular root hair present and maximum water absorption take place.
• Cells of root cap contain abundant golgi bodies which secrete mucilage to lubricate soil particles.
• Mangrove grown in saline marshes and minute thods aerating pores of pneumatophores are nematodes.
• Parasitic root of Cuscuta are called haustaria or sucking root. Cuscuta is dicot plant with zero cotyledon.
Rootless plant→ Utricularia, Wolffia, Epipogium, Balanophyllum, Cuscuta, Ceratophyllum.
Plantless roots→ Areceuthobium, Rafflesia, Sapria, Podastemon, Monotrapa.
Inulin- Roots of Dahlia store food in form of inulin(a water soluble polysaccharide)
Bended root- Momordica
Stilt/ brace root- Sugarcane, Maize, Screw pine(@SMS)
Climbing root- Vanilla, Ivy, Pothos, Pieper OR Beetle nut (@VIP Pan)
Prop/Pillar root- Ficus bengalinis
Butress root- Simal, Peepal
Photosynthetic root- Trapa, Taeniophyllum, Tonospora
Epiphyllous root- Salvinia
Reproductive tap root- Sisoo
Root Thorn- Pothos, Acanthorhiza
2.Leaf
• Dicot leaf showing parallel venation:
Calophyllum, Corymbium, Eryngium (@CCE)
• Monocot leaf showing reticulate venation:
Smilax, Aroid, Dioscorea, Colocasia (@SAD)
• Bignonia- Hook climber
• Margin of lamina into spines. eg. Argemone maxicana
• Pitcher like modifiacation of leaf lamina for water storage found in Dischidia.
• Winged petiole→ Citrus → One leaflet to tip of petiole (@COW)
• Cotyledonary leaves→ Cucumber, Tamarindus, Castor, Beans (@CTC Beans)
• Sheathing leaf base in monocots.
• Whole leaf into spine- Opuntia
• Stipule into spine- Zizyphus, Acacia
• Margins of leaf modified into spines- eg: Argemone maxicana
• Leaf tip into tendril- Glory lily( Glorisa)
• Whole leaf into tendril- Lathyrus odoratus (Wild Pea)
•Anterior leaflet into tendril- Garden Pea
• Leaf stipule into tendril- Smilax
• Axillary bud into tendril- Passiflora
• Terminal bud into tendril- Grapes (Vitis)
• Extra axillary bud into tendril- Cucurbitaceae
• Floral bud into tendril- Antigonon
• Petiole:
→Winged- Citrus and Sweet pea
→Floating/Spongy- Eichhornia
→ Tendrillar- Pitcher plant(Nepenthes), Nasturtium, Clematis
• Phyllode( flattened, green and photosynthetic petiole) -Parkensonia, Australin acacia
• Reproductive leaves- Begonia, Bryophyllum
• Phyllotaxy- Arrangement of leaves
• Vernation- Arrangement of leaves with respect to each other in bud condition.
• Leaf tentacles- Drosera ( Sundew plant)
3.Stem
→ Nodes and internodes are always present.
→ Lateral branches of stem develop from cortex exogenously.
Culm- All grasses
Caudex- Coconut, Cycas
Decurrent or Deliquescent- Ficus, Magnifera
Excurrent- Conifers
Pseudostem- A caulescent plant. eg: Banana, Onion, Zingiber
Bougainvillea- Thorn, Climber
Lianas- Tropical Forest
Phyllode- Parkensonia
Phylloclade- Opuntia, Muehlembeckia, Euphorbia (@MOE)
Cladode- Asparagus, Ruscus (@CAR)
Remember POA( Phyllode, Phylloclade, Cladode)
Rhizome- Horizontal growing underground stem with distinct nodes and internodes eg: Banana, Ginger, Turmeric
Corm- Vertical growing
• New banana plants develop from sucker.
• Stolons are long distance runner and offsets are short distance runner.
•Prickles of rose are exogenous in origin.
Agave- Liliaceae plant, century plant, monocarpic, monocot plant, showing secondary growth, vegetative reproduction by bulbil.
Bulbil- Diascorea, Agave, Oxalis, Onion.
4.Inflorescence
Solitary axillary- China rose
Solitary terminal- Poppy plant
Actinomorphic, Bisexual, Central→ Disc Floret(@ABCD)
Zygomorphic, Unisexual, Peripheral→ Ray Floret
Raceme- Raddish
Panicle- Male flower of Maize, Cassia, Delonix
Spike- Calistemone( Bottle brush), Achyrenthes ( Chaff flower)
Catkin or amentum- Mulberry, Salinx (@ MuSa)
Spadix- Female maize flower, Banana, Coconut
Umbel- Coriander
Corymb- Candytuff
Head or capitulum- Compositae
Helicois- Begonia, Drosera(@ Hell in BeD)
Corpoid- Renunculus, Potato, Cotton
Bichasial/ Biparous chime- Dianthus, Jasmine, Bougainvillae (@ DJ Bajao)
Multichasial- Calotropis, Ascelpias (@ CAM)
Hypanthodium- Ficus( female top, male bottom, Gall flower middle)
Cyathium- Euphorbia
Verticellaster- Osimum, Mint, Salvia
• Trapdoor mechanism of pollination→ Ficus
• Translator mechanism of pollination→ Calotropis
• Turnpipe mechanism of pollination→ Salvia
• In Cyathium, ratio of female to male flower is 1: Many
Edible inflorescence in Cauliflower, Mulberry, Ficus, Spadix in female maize.
Involucre found in Cyathium, Capitulum, Umbel (@ CCU)
5.Flower
• Cleistogamous (Flower never open) eg: Oxalis, Viola, Mirabilis
• Commellina has both cleistogamous and chasmogamous
Largest flower- Rafflesia
Smalleest flower- Wolffia
• Ovary inferior( Epigynous) in Compositae, Cucurbitaceae (@ CC)
• Incomplete flower- Any one of the four whorls is missing. eg: Liliaceae, Graminae, Ray floret of sunflower etc
In compositae, sepals are modified into Pappus( hairy sepals) for dispersal of fruits by Parachute mechanism.
• Cruciform- Four free petals arranged in the form of cross. each petal called clawed petal or ungiculate petal.
• Campanulate or bell shaped- Cucurbita
• Infundibulum or funnel shaped- Datura, Stramonium, Petunia
• Tubular- Disc Floret of Sunflower
• Papilinaceous- Butterfly shaped
• Masked/ Personate- Antirrhinum( Snap dragon)
• Lingulate/ Strap Shaped- Ray floret of Sun flower
• Perianth- Liliaceae & Graminae
↓
Lodicules in Graminae
Aestivation
• Valvate- Brassicaceae, Mimosaceae
• Twisted/ Contorted- China Rose
• Imbricate- Caesalpiniaceae (1+1+3)
• Quincuncial- 2+2+1
6.Fruit
• Largest fruit- Lodoicea maldavica( double coconut)
• Smallest fruit- Orchid seed (dust seed)
Follicle- Calotropis
Legume/Pod- Pea, Bean, Gram
Siliqua- Cruciferae
Berry- Tomato, Grapes, Banana, Guava
Cypsela- Compositae
Caryopsis- Graminae
Pome- Apple, Pear
Pepo- Cucurbitaceae
Balausta- Pomegranate
Hesperidium- Lemon, Orange
Drupe- Mango, Coconut, Plum
Lomentum- Groundnut
Amphiscara- Aegle marmelos( Wood apple)
Sorosis- mulberry, Jackfruit, Pineapple
Syconus- Ficus Sorosis and syconus}Developed from inflorescence
Regma- Castor, Euphorbia
Etaerio of follicle- Calotropis, Vinca
Etaerio of berry- Custard apple
Etaerio of achenes- Rose, Strawberry, Lotus, Ranunculus
Etaerio of drupe- Raspberry
True fruit- Litchi, Oak, Castor, Water Chestnut (@LOCC)
Edible part:
Maize- endosperm and embryo
Litchi- Fleshy aril
Walnut- Cotyledon
Grape- Placenta and pericarp
Guava- Placenta, Pericarp, Thallamus
Banana- Mesocarp and endocarp
Cucumber- Mesocarp and endocarp
Ficus: Peduncle and seeds
Pineapple- Axis, Perianth, Pericarp
Rice- Endosperm and Embryo
Mango- Fleshy mesocarp
Coconut- Endosperm
Tomato- Placenta and pericarp
Pomogranate- Testa
Mulberry- Perianth
Pear/ Apple- Thallamus
Clustard apple- Mesocarp
Jack fruit- Axis, bract, perianth & seeds.
Betelnut- Endosperm
7.Seeds:
• Study of seeds- Spermalogy
• Seed has two parts- seed covering and kernel or grain
• Seed covering
→ single (testa)
→ double (outer testa- inner tegmen)
• Seed cover arise from integument.
• Albuminous seed (Food material in endosperm)
→ Dicot- Castor, Cotton, Papaya
→ Monocot- Wheat, Maize, Coconut
• Exalbuminous seed( Food material in cotyledons)
→ Dicot- Pea, bean, cucurbitaceae
→ Monocot- Money plant, Vallisnaria
Germination of seed:
• Hypogeal germination- Epicotyl germinate first
Mainly in monocot
except- Dicot- Pea, Gram, Bean, Cycas
• Vivipary germination- germination of seed inside fruit. eg: Rhizophora
• Epigeal germination-
Hypocotyl germinate first
In Dicots- Mustard, castor, Pinus
• Dispersal of seed-
Autochory ( explosive mechanism): Balsam, Bauhinia, Castor, Cucumber
Wind
→ Powdery- Orchids, Grass
→ Winged seed- Moringa, Cinchona, Pinus ( @PCM)
→ Winged fruit- Acer, Dioscorea, Shorea, Hiptage
→ Parachute mechanism-
Pappus- Tagetus, Sonchus
Coma-Calotropis, Alstonia
Hairs- Cotton
Persistent hairy style- Clematis, Norvelia
Censer mechanism- Papaver, Argemone
Water- Coconut, Lotus
Myrmechory( ant)- Trilium and Anemone