THE AMERICAN HOTANIST. 109 



Upon a closer examination of the plants, for those with 

 three parted flowers have stems or trunks in which the 

 wood-btmdles are scattered through the pith — a very good 

 illustration of \vhich maj- Ix; found in the corn-stalk- 

 while those with five-parted flowers have the wood- 

 Lundles arranged in a circle around the central pith such 

 as is seen in a cross-section of an ordinary tree like the oak 

 and maple. We find further that these plants with three 

 parted flowers have onlj^ one seed leaf or cotyledon, while 

 the plants with five parted flowers have two cotyledons. 

 Thus when we plant corn, which belongs to the first 

 group, a single spire of green comes up ; but when we 

 plant loeans which belong to the latter, we expect every 

 one to come up with two seed leaves which soon spread 

 out to the sun. Of course, there are many plants with 

 two cotyledons that do not bear them above the surface 

 of the soil, but they will be found upon examination of 

 the seed. Now while the number of the floral ]3arts, 

 the venation of the leaves and the structure of the stems 

 maybe depended upon to separate the plants of these two 

 groups, the most distinctive character is found in the 

 cotyledons and therefore one is called the monocotyledons 

 and the other the dicotyledons. The beginner, interested 

 in fixing these diflerences in mind, would do well to write 

 down these terms in their order, adding the characters 

 that distinguish each. 



THE MONOCOTYLEDONS. 



There are about twent\^ thousand species of mono- 

 cotvledons in the world. These are classified according to 

 their relationships into Genera, the genera are arranged 

 into larger groups called Families and the families them- 

 selves form still larger groups called Orders. Ten of these 

 orders are represented in Eastern America, six belonging 

 to a division in which the pistils are separate or distinct, 

 and four to one in which the pistils are united. Bearing 

 in mind what has been said regai'ding the evolution of the 

 flower, we see that the section with pistils separate, or 

 apocarpous, is least specialized and we will therefore begin 

 with that. The first order, the Pandanales takes its name 



