FLOWERS 



entirely distinct, each one having its own 

 ovary, style, and stigma. For example, 

 in the buttercup there is a little mound in 

 the center of the flower made up of nu- 

 merous pistils, each consisting of a single 

 carpel. It is evident, therefore, that a 

 pistil may consist of one carpel or several 

 carpels, and that in the latter case the 

 carpels may be more or less completely 

 united. The sure indication of a carpel is 

 that each carpel bears its own ovules. 



In some flowers there is but a single 

 carpel, as in peas and beans, whose pods 

 have developed from a pistil consisting of 

 a single carpel, as is indicated by the sin- 

 gle lengthwise set of seeds. 



In some plants the flowers do not have 

 all the four parts described above. In 

 some cases the petals may be lacking, the 

 one set of perianth parts represented be- 

 ing regarded as the calyx, although it 

 may look like a corolla, as in the clematis 

 or anemone. Such flowers are said to be 

 apetalous, which. means "without petals." 

 In other cases both the calyx and corolla 

 mav be w^anting. the flower consisting of 

 only stamens and carpels. Such flowers 

 are spoken of as naked. 



In other flowers the stamens may be 

 lacking, and as the pistil is the only es- 

 sential part present such flowers are said 

 to be pistillate. It m'ay be counted upon, 

 however, that if there are pistillate 

 flowers there are also corresponding 

 staiuinatc flowers in which the pistils are 

 lacking and the stamens present. In such 

 cases Ijoth staminate and pistillate flowers 

 may occur on the same plant, or they may 

 occur on different plants, so that there 

 may be not only staminate and pistillate 

 flowers, but also staminate and pistillate 

 plants. 



It also sometimes happens that stami- 

 nate and pistillate flowers are also naked, 

 so that in such cases the flower is repre- 

 sented by stamens alone, or even by a 

 single stamen, or by carpels alone, or by 

 a single carpel. It would be hard to 

 imagine a more simple flower than one 

 composed of a single stamen or a single 

 carpel. Such flowers may be found in 

 the willows. 



In this study of the lily it should be ob- 

 served that the number three runs 

 through all the parts of the flower. The 

 flower formula may be expressed as fol- 

 lows: sepals 3, petals 3, stamens 3 plus 3. 



carpels 3. This number is established in 

 many families related to the lilies, and is 

 one of their characteristic features. 



In other groups of flowering plants a 

 different number is established, the num- 

 ber five being the most common. For 

 example, in the common wild geranium 

 the flower formula is as follows : sepals 5, 

 petals 5, stamens 5 plus 5. carpels 5. In 

 still other flowers the number four is 

 established. 



In many common flowers it will be no- 

 ticed that no definite number is estab- 

 lished, or that it is not completely estab- 

 lished. For example, in the common wild 

 rose there are 5 sepals and 5 petals, but 

 an indefinite number of stamens and car- 

 pels ; while in the water lily there is no 

 definite number established, the sepals 

 being usually 4, and the other parts in- 

 definitely repeated. 



In those flowers in which some num- 

 ber is definitely established, it often hap- 

 pens that one set may be reduced in 

 number, and this is usually the carpel set. 

 In the families of highest rank among 

 flowering plants, such as the figworts, 

 mints, and composites (sunflowers, 

 asters, dandelions, etc.) the flower for- 

 mula is sepals 5, petals 5. stamens 5, and 

 carpels 2. 



Another fact shown by the lily flower 

 is that the different sets alternate with 

 each other in position. The three petals 

 do not stand directly in front of the three 

 sepals, but in front of the spaces between 

 the sepals. In the same way the three 

 outer stamens alternate with the petals ; 

 the inner stamens alternate with the outer 

 ones ; and the three carpels alternate with 

 the inner set of stamens. It is very un- 

 common to find one set standing directlv 

 in front of the next outer set. and this 

 position opposite the other set always 

 needs some special explanation. As a 

 rule, therefore, the flower sets alternate 

 with one another, but in some cases a set 

 mav be opposite. 



The history of a flower does not end 

 with the opening of the blossom. If the 

 stigma has succeeded in receiving some 

 pollen, and the pollen has succeeded in 

 doing its work, the ovules within the 

 ovarv become gradually transformed into 

 seeds, and the ovary becomes trans- 

 formed into the fruit, the outer sets of the 

 flower usually disappearing. In the lily 



