Angiosperm Morphology Introduction

Angiosperms are a group of flowering plants that represent a major community in the plant kingdom. Angiosperms occur in all typical habits and constitute a very useful group of plants for animals and human beings. They include about 2,50,000 species distributed all over the world. They are the most highly evolved group of plants and appeared on Earth about 130 million years ago.

The adult plant body of angiosperms is a sporophyte. It is differentiated clearly into two regions. The ascending portion of the plant body is called as shoot system and the descending portion is called as root system.

fig. 27.1 - Adult Plant Body of an Angiosperm

The shoot system has an axis that is called stem which is differentiated into nodes and internodes. At the nodes, lateral appendages called leaves arise. The leaves are green in colour. Also seen at the nodes are structures called branches and flowers. The branches also produce leaves and flowers. Flowers are the reproductive structures. The tip of the stem usually has a terminal bud which brings about linear growth. In the axil of the leaf (at the angle between a leaf and the stem), there is an axillary bud which brings about the formation of a branch or an inflorescence or a flower.

There are two kinds of functional structures in an angiosperm plant body, namely, the vegetative parts and the reproductive parts. The root, stem, branches and leaves represent the vegetative parts while flowers represent the reproductive part.