Samacheer Class 11 Bio Botany - Vegetative Morphology

I. Avicennia & trapa
Avicennia
Trapa (water chestnut)
Live in marshy leaves
Live in aquatic habitat
Has negatively geotrophic root known as respiratory roots-with pneumatophores help in exchange of gases
Has photosynthetic or assimilatory roots – help in photosynthesis.
II. Banyan & silk cotton
Banyan
Silk cotton
Has pillar roots- grow vertically downward from the lateral branches to soil -to give additional support.
Has broad plant-like outgrowths develop obliquely towards the base all around the trunk – to give support.
III. Fusiform and Napiform root
Fusiform
Napiform
Roots are swollen in the middle and tapering towards both ends (like a spindle-shaped Eg. Raphanus sativus
Roots broad and suddenly tapers like a tall at the apex (top-shaped) Eg. Beta vulgaris

Root Climbers
Stem Climbers
Climb with the help of adventitious root( arise from the node) Eg: Piperbetal, piper nigrum
No special climbing structures – stem itself coils around the support Eg: Ipomoeaellittoria

Sympodial
Monopodial
Determinate — growth
Terminal bud ceases -to grow-and further growth by lateral buds- Eg. Cycas
Indeterminate growth
TerminaI bud — grows uninterrupted and produce several lateral branches — Eg. Polyalthi

Pinnately reticulate (unicoastate)
Palmately reticulate (multicoastate)
One mid rib in the centre with many laterlal braches
Eg: Mangifera indica
Several veins arise from the help of peticole & run parallel & unite at the apex – 2 types
Divergent Eg: Borassussflabellifereg,
Covergant Eg. Paddy
Part – II
11th Bio Botany Guide Vegetative Morphology Additional Important Questions and Answers
Choose the Correct Answer:

Morphological features are important in determining the productivity of crops. Morphological characters indicate the specific habitats of living as well as the fossil plants and help to correlate the distribution in space and time of fossil plants. Morphological features are also significant for phylogeny.

• Cauducuous (fagaceous)- falling off soon after formation – Opuntia
• Deciduous – Falling at the end of the growing season (winter& summer-leaf less)- Erythrina indica
• Evergreen- persistent throughout the year tree never remain leafless Mimusops
• Marcescent- no falling-but withering on the plants – Fagaceae

Primary root is the direct prolongation of the radicle. When the primary root persists and continues to grow as in dicotyledons, it forms the main root of the plant and is called the tap root. Tap root produces lateral roots that further branch into finer roots. Lateral roots along with their branches together called secondary roots.

Horks
Spines
Prickles
Organ of climbing
Protective & adaptive to xeric condition
Protective & adaptive to xeric condition
Leaf modification terminal 3 leaflets – modified into sharp sliff -curved hooks (like nails of eat)- bignonia unguiseatr
Leaf modification – opuntia Leaf & stipule modification- Euphorbia Leaf surface or margin of leaf – Argemone mexicana
Our growth from epidermal cells of stem or leaves – Rosa spp

Type
Definition
Examples
1. Alternate Spiral
Only one leaf — each node successive nodes have alternate – in a spiral manner
Hibiscus
2. Alternate bifarous
Leaves in 2 rows – alternatively
Polyalthia
3. Opposite superposed
2 leaves in each node opposite in same direction in successive nodes
Eg. Guava
4. Opposite deeussate
One pair of leaves at right angles to the next lower pair
Eg.Calotropis
5. Temate
3 leaves at each node
Eg.Nerium
6. Whorled or verticulate
More than 3 leaves at each node
Eg.Allamanda
7. Leaf Mosaic
Upper leaves with short petiole lower leaves have long petioles
Eg.Aealypha

Definition:
Morphologically 2 different kinds of leaves in the same plant is called heterophylly.
Types-2
* Structural
* Developmental
1. Structural – In Limnophyllaheterophylla, aquatic plant half of its plant body is submerged and half is above water level. Here aerial leaves are normal & the submerged leaves are highly dissected.
2. Developmental – In Sterculiavillosa Varying structure during different developmental stages- Young leaves – lobed or dissected Mature leaves – entire

Pitcher plant
Bladder plant
Grow in terrestrial habitat – where there is scarcity of nitrogen in the soil
Root less free-floating or slightly submerged aquatic plant
All parts of leaf modified, specially the leaf lamina- as pitcher with lid to trap insects Eg. Nepenthus
Leaf highly segmented and some segments of leaf modified into the bladder with trap door to trap aquatic animalcules Eg. Utricularia

Excurrent
Decurrent
Main axis – continuous growth lateral branches shorter and tapper towards tip conical appearance Ex: Polyalthia
Lateral branches more vigorous growth- giving rounded spreading appearance Ex: Mangifera

In cat’s nail (Bignonia unguiscati) an elegant climber, the terminal leaflets become modified into three, very sharp, stiff, and curved hooks, very much like the nails of a cat. These hooks cling to the bark of a tree and act as organs of support for climbing.
Phyllode- It is a winged leaf petiole or stalk or rachis Eg. Nepenthus – modified to perform the function as leaf
Acacia auriculiformis Leaf- petiole modification to do photosynthesis
Essay Question – Five marks

Types
Definition
Examples
Reclinate
Upper half of leaf blade bent upon lower leaf
Eriobotry a japonica
Consolidate
Lengthwise folding along mid rib
Guava, potato Bauhenia
Plicate
Repeatedly folded longitudinally along ribs – zigzag manner
Borassus
Cricinate
Leaf rolled apex to base
Ferns
Convolute
Leaf rolled from margin from one to other
Musa members of Arecaceae
Involute
Two margins rolled on the upper surface of leaf towards mid rib.
Lotus lily
Crumpled
Irregularly folded
Cabbage

Runner
Sucker
Prostrate branch of aerial stem creeping on the ground and rooting at nodes.
Ex: Centellacynodondaetylon
The underground stem grows obliquely upwards give rise to a new plant.
Ex: Chrysanthemum Bambusa, Musa

Plant morphology is also known as external morphology deals with the study of shape, size, and structure of plants and their parts like (roots, stems, leaves, flowers, fruits, and seeds).

The axillary bud ensheathes by the scale appears as eye-like on the potato surface each and every eye can develop into a potato plant.
‘S’ Scale Leaf Auxiliary bud