INTRODUCTION 



The name cycads is likely to sound strange to those 

 who are not botanists, but the group itself is represented 

 in greenhouses by some of our most familiar decorative 

 plants. The sago palm, Cycas revoluta, whose rigid 

 fernhke leaves are in such demand on Palm Sunday and 

 on funeral occasions, is the best-known representative, 

 and many regard it as the most beautiful. 



For an introduction to the cycad family nothing 

 would serve better than the Mexican Dioon edule (Fig. i). 

 The short, stocky trunk, covered by an armor of old 

 leaf bases and surmounted by a crown of dark-green 

 leaves, is characteristic and makes the plant look like 

 a small tree fern or palm. By the natives the various 

 cycads are usually called palms, so that we have the 

 sago palm, bread palm, Dolores palm, and other palms; 

 but to the botanist, who knows that they are intimately 

 related to the ferns and not even distantly related to the 

 palms, they look more like ferns. And they deserve to 

 look like ferns, for they have retained the fern leaf of 

 their ancestors from the Paleozoic age down to the 

 present. The scientific name of the family is Cyca- 

 daceae, but botanists generally call the plants cycads. 



The genus Cycas was called the "sago palm" because 

 the stem and seeds contain so much starch; but all the 

 genera contain an abundance of starch, and some of 

 them have been exploited commercially. The growth, 

 however, is extremely slow and must always prevent 



