~LTHOUGH we accept as plants are green, their green

axiomatic

the

fact

that

,~ pigment, chlorophyll, is remarkable in the biological world. It makes plants,

~te literally, providers of energy to the world s host of living organisms--man

all the other animals, and even nongreen plants. For it is chlorophyll that

~s plants the unique ability to utilize the energy of sunlight for the manufac-

~0ffood; and this in turn means that fungi and animals can use plant com-

I~ands for energy and for their own building materials, either directly or

~ugh complex food chains. And to man, of course, Plants furnish thousands

:other useful products beyond the primary benefits of food.

..We: know from the fossil record that plants appeared on this earth hundreds

~millions of years ago. Although the actual origin of living matter continues

ibe a controversial question, it is likely that the earliest living "organisms,"

hose composition is unknown, derived the energy for growth and reproduc-

m by simple chemical means. Presumably they broke down chemical com-

~unds in their watery environment; eventually they utilized the sunlight by

.~ns of photoreceptive pigments. However it occurred, from some unknown,

i"imitive green organism the continuous process of evolution has given us all

~e wonderfully diverse and fascinating world of plants we live in today. They

found almost everywhere, and the adaptations they have made to special

~vir0nments, as the cactus family has to deserts, are as extraordinary as any-

~ng in nature.