FLOWER CHART xvii 



shows but one step of advance, we must place it in the groups between 

 the first and second cross-lines of advance, or in those between buttercups 

 and primroses. By looking these over, it is quickly seen that the formula 

 is exactly similar to that of the geranium family, so we conclude the flower 



belongs to that order. A flower with the formula ' a ^ has two steps 

 of advance, one that of a united or compound pistil and the other an 

 elevated corolla. The united pistil and the 3-plan of flower start us along 

 the left-hand line and the two steps of advance place the flower between 

 the second and third cross-lines, or in the iris group. The flower-formula 



S5 

 for still a third flower is Ca(5) Co(5) The steps of advance indicated are 



P(3) 



united pistils, raised calyx and corolla, and united corolla. The raised 

 corolla and the number 5 start the flower along the middle line, while the 

 three steps of advance bring it well towards the top of the line above the 

 line indicating union of corolla, where it is seen to belong to the bluebells. 

 These are clear-cut types, however, and for the sake of illustrating those 

 which are not so distinct, let us take a few other flowers and follow them 

 up. If we have a flower with three separate pistils, many stamens, an 

 irregular calyx of 5 parts and only 2 petals, the formula would be 

 Ca 2+2U Co 2 S P 3 . The only step of advance apparent in this formula 

 is that of the irregular corolla. The rule is that one must start at the bot- 

 tom of the chart and proceed upwards, taking the cross-lines of advance 

 in order and skipping none. Now, since the step of advance indicated here 

 is the fourth step in order, there is nothing to do but stop right at the be- 

 ginning in the buttercups, since the flower is the monkshood (PL 1, fig. 1), 

 one of the irregular buttercups. Irregular flowers may occur in any group, 

 but if the other steps of advance are always considered first in order of 

 occurrence, this fourth one will not be of determining value except when 

 it occurs as a third or fourth step, according to the line of development. 

 If one discovers a lily with a united corolla, the fact that the flower has 

 the plan of three and not the fact that it possesses union will be the de- 

 termining factor which places it on the left-hand line, where union of 

 petals occurs as an exception. If the beginner starts with clear-cut types, 

 such as many of those in the color-plates, he will soon acquire the ability 

 of recognizing members of the same group with facility and derive a 

 great deal of pleasure from so doing, as this ability is of use wherever 

 flowers grow. The general types are similar all over the world and only 

 the minor points which determine the smaller groups differ. 



