Leaf

"Plants Organ"
Leaf
Arranged by group 3 :
Nidya Fadhilah
Sahla Eka Novianty
Siti Alifah Nurjanah
Utami Rahmi Hartini
Wida Fitriyah
Shinta Dewi Triandiny

Leaf comes from embryo inside the seed that is cotyledon. The green color of the leaf is caused by the existence of chlorophyll (green substance of the leaf).
a)Structure of leaf
1)Morphology
A complete leaf consists of sheath, petiole, and blade.

•Bone Shapes
Bone shapes are also different kinds of leaves, among others, pinnate, arched, palmate, and parallel.

a. Pinnate
Bone leaves in this type of arrangement like the fins of fish. Examples of plants that have this type of bones are the bone leaves of guava, mango and rambutan.

b. Curved
Bone shaped like a leaf curved lines curved. Bone leaves of this type can be found in various plants in the environment around us. For example, betel leaf bones, yam, and velvetleaf.

c. Palmate
Bone palmate leaves shaped like human fingers. For example, bone papaya, distance, cassava, and cotton.

d. Parallel
Bone shaped leaves parallel lines parallel. Each leaf ends of the bones fused. For example, bone cane leaves, rice, and all types of grasses.

e. Simple leaf and compound leaf
Simple leaf is the leaf which has a single leaf on each stem. The compound leaves are leaves that have a few leaves on each stem.



2)Anatomy
In broad outline, the anatomically arrangement of the leaf from top to down is as follow:

a)Cuticle layer, is the top layer and hard to be penetrated by the water because it contains chitin and wax substances.

b)Upper epidermis is the outer tissue, which function to protect parts of leaf beneath it. In several plants, mostly water plants, this layer has pores which is called stoma (plural: stomata) or leaf mouth. The function of stomata is as the transpiration regulator and the place for the gaseous exchange.

c)Mesophyll (flesh of leaf), consists of two kinds of tissues, fence tissue/palisade parenchyma and spongy parenchyma in which photosynthesis takes place. Fence tissue consists of parenchyma cells which contains chlorophyll and densely arranged like a fence. Spongy tissue consists of parenchyma cells, which contain a little chlorophyll; the intercellular space is quite spacious and forms an arrangement like a sponge.

d)Vascular bundle consists of xylem and phloem, which are in petiole and leaf veins.

e)Lower epidermis is the lowest layer of the leaf. Generally, more stomata are found in the lower epidermis, but the cuticle layer thinner or absent.

b)Function of Leaf

1)The place for the photosynthesis process.
2)The place for respiration, transpiration, and guttation process.
3)To catch a prey as in pitcher plants.
4)To protect from animal disturbance as in cactus spines, this is modification of leaf.
5)As a vegetative reproductive organs as in kalanchoe.