Anatomy of Flowering Plants

| 89

MØÑØÇØTÝLËDØÑØÜS (ÏSØBÏLÅTËRÅL) LËÅF

The anatomy of monocot

leaf is like that of the dicot

leaf in many ways, however it

shows following differences:



Stomata

are

present

on both surfaces of the

epidermis



Mesophyll is not differentiated into palisade and spongy parenchyma.



In grasses, certain adaxial epidermal cells along the veins modify

themselves into large, empty, colourless cells. These are called bulliform

cells. When the bulliform cells have absorbed water and are turgid, the

leaf surface is exposed.



When they are flaccid due to water stress, they make the leaves curl

inwards to minimise water loss.

(NEET 2019)



Parallel venation is reflected in the near similar sizes of vascular bundles

(except in main veins).

(AIPMT 1992, 1990)

SËÇØÑDÅRÝ GRØWTH

3

2

1

The growth of the roots and stems in length with the

help of apical meristem is called the primary growth.

Apart from primary growth, most dicots exhibit an

increase in girth. Secondary growth is the increase in

girth of dicot plants.

Tissues involved in secondary growth are the

two lateral meristems: Vascular cambium & cork

cambium.

Adaxial epidermis

Xylem

Mesophyll

Sub-stomatal cavity

Abaxial epidermis

Stoma

Phloem