DIVISION INTO FAMILIES AND GENERA. 39 
place supplied by scales; and sometimes having the stamens 
and pistils in different flowers on the same, or even on different 
trees. They are often disposed in catkins or aments, which are 
the cylindrical, pendulous tassels which are seen, early in spring, 
on the birch and alder, for example; or clustered and horizontal 
near the ends of the branches of the pine. In the plane tree they 
are globular. In my arrangement, I shali begin with those plants 
whose flowers are simplest or least complete, consisting of sta- 
mens only or seed-vessels only, sustained and protected by one 
or two scales, and usually disposed in catkins; and proceed, in 
order, to those which have a calyx, but no corolla; those which 
have calyx and corolla; first of one petal; and lastly to those 
with a corolla of many petals with many stamens and pistils— 
whose flowers are most complete. 
An example will show the way in which the table may be 
used. 
Suppose that a person has found a tree, with rough, simple, 
alternate leaves, flowers of two kinds, some with 5 stamens and 
no style, others with 5 stamens and 2 styles, with a calyx but 
no corolla, and a fleshy, berry-like fruit with a stone containing 
a single seed. He wishes to ascertain what the tree Is. He 
begins with the first question, and, as the flowers are not in 
catkins, is referred to question 9. By that, as the leaves are 
alternate, he is referred to 20; thence, as the stamens are fewer 
than 10, to 21; thence, as the flowers are regular, to 225 as 
the flowers have not a corolla, but only a calyx resembling a 
corolla, he is referred to 23, and thence to 24; they have 2 styles, 
and he is referred to 28; 5 stamens, to 55, ‘and he learns that 
his tree belongs to the Elm Family. The answer to question 
55 shows him that it is the Nettle Tree, and is described in the 
second section of the tenth family, which he will find indicated 
by X. 2. on the left of the title on page 307. 
DIVISION INTO FAMILIES. 
Flowers in catkins. 2. 
Flowers not in catkins. 9. 
Kd» 
") 
Leaves needle-shaped or scale-like, mostly evergreen. 43. Pine Famt- 
2 uy. I. 
Leaves not needle-shaped or scale-like. 3. 
