HOW TO USE TIIE POPULAR FLORA. 
101 
and the petals, are five. So the plant belongs to Class I. Proceed then with the 
u Key to the Families or Orders of Class I.” on page 106. This class has two 
subclasses. So you next ask, — 
To which subclass does the plant belong, to Angiosperms or to Gymnosperms ? 
For the character of the Gymnosperms, see the end of the Key, at the foot of 
page 111 ; that of Angiosperms begins the Key. The centre of the flower we are 
examining is occupied with a great number of small one-seeded pistils, each tipped 
with its short style and stigma ; and the ovary is a closed bag containing an ovule 
or young seed. So the plant clearly belongs to Subclass I. Proceed then with 
the Key ; which leads you next to ask, — - 
To which division does the plant belong, — the Polypetalous ? (in black letters 
immediately under the subclass), or the Monop etalou s ? (top of page 109), or the 
Apetalous ? (lower part of page 110). Plainly to the first or Polypetalous division; 
for there is both a calyx and a corolla, and the latter is of five separate petals. 
This division, in the Key, subdivides into, “ A. Stamens more than 10,” and 
“ B. Stamens 10 or fewer” (p. 107). Our plant has many stamens, and so falls 
under the head A. 
This head subdivides into three (marked 1, 2, 3), by differences as to where and 
how the stamens are borne. Pull off* the calyx and the corolla, or split a flower 
through the middle lengthwise (as in Fig. 238), and you will plainly see that the 
stamens stand on the receptacle, under the pistils, unconnected either with the calyx, 
or the corolla. So the plant falls under the head 1. 
Under this is an analysis of some of the characters (i. e. distinguishing marks) of 
the fifteen or sixteen families which belong here. The lines that are set in are 
subdivisions under the longer line above them. The lines which rank directly un- 
der one another (and begin with the same or a corresponding word) make alter- 
natives, among which you are to choose that with which your plant agrees. In 
this instance the lines of the first rank here begin with the word “ Pistils ” or 
“ Pistil,” and there are five of them. Try the first : “ Pistils more than one, 
entirely separate from each other.” That is the case with our plant. Under this 
line, in the next rank, is a triplet, or a choice between three. Our plant is an “ herb, 
with perfect flowers,” and so falls under the first line. Under this is a couple 
of equivalent lines, relating to the leaves. Our plant agrees not with the second, 
but with the first of these ; and that line ends with the English name of the 
family we are seeking for, viz. the Crowfoot Family, and refers to page 112, 
where this family is described. 
