Page 13 - Lesson Notes-Morphologyof flowering plant

Functions of Leaves
The leaves have many primary and secondary functions.
Primary Functions
(a) The most important function of leaves is photosynthesis with the help of sunlight
and carbon dioxide.
(b) Leaves contain stomata through, which gaseous exchange occurs,
(c) Leaves are the site of transpiration.
(d) They protect axillary and terminal bud from mechanical injury and desiccation.
Secondary Functions
(a) Leaves store food as in the leaf base, e.g., Onion.
(b) Leaves change into phyilodes to protect against transpiration.
(c) Storage of water in the cells of some succulent plants, e.g., Aloe.
(d) In Salvinia, one leaf of each node is changed into roots that act as balancer for
floating.
(e) In some leaves like of Euphorbia, the young leaves are brightly coloured to attract
insects for pollination.
The Inflorescence
The arrangement and distribution of flowers over a plant is called inflorescence.
The inflorescence can be of following three types
1. Racemose Inflorescence
In racemose type of inflorescence, the main axis continues to grow and the flowers
are borne laterally in an acropetal succession (the older flowers are found towards
the base and younger ones at the apex) or centripetal (older towards periphery and
younger towards centre).