CHAPTER 1Morphology and tissuesyste

CHAPTER 1
Morphology and tissue
systems: the integrated
plant body
General background
Because each organ of the plant will be discussed in detail in later chapters,
this section is intended only to be a reminder of basic plant structure and
arrangements of tissue systems. It is not intended to be comprehensive,
and by its very nature it oversimplifi es the complex and wide range of
form and organization existing in the higher plants. When a specialized
term is fi rst used, it is normally defi ned. The glossary forms an essential
part of the book, and should be consulted if the meaning of a term is
not clear.
This book concentrates on the vegetative anatomy of land plants, and in
particular on monocotyledons and dicotyledons (fl owering plants, angiosperms,
with the seeds enclosed in carpels). Some anatomical features of
conifers (gymnosperms – plants with seeds but without carpels fruits, enclosing
the seed) are also described. Monocotyledons (Fig. 1.1) are fl owering
plants that when the seed germinates start life with one seed leaf, and
lack the tissues that form new (secondary) growth in thickness, the vascular
cambium, and a long-lived primary root. Examples include the grasses, orchids,
palms and lilies. Dicotyledons (Fig. 1.2) are also fl owering plants but
have two seed leaves, and like the conifers have stems that generally have
the ability to grow in thickness through a formal vascular cambium, and
have a long-lived primary root. Examples of dicotyledons include the bean,
rose and potato families, and the conifers include such plants as pines,
larches and araucarias. There are, of course, other features that distinguish
the angiosperms from gymnosperms (e.g. reproductive structures and
reproductive cycle).
The plant organs are shown in Figs 1.1 and 1.2. Most land plants have
roots, which anchor them in the ground, or attach them to other plants (as
in epiphytes). Roots also absorb water and minerals.