The Composites. iS5 



the innermost thing in the flower, you know that the outer coats of this 

 body are theoretically composed of the adherent calyx and the organs 

 uithin it. So, strictly, the sunflower " seed " is a one-seeded fruit, as a 

 cherry or walnut is, in which last the outer husk answers to the pulp of the 

 cherry. The fruit of the compositae never opens. It is called an achetiium. 

 Within you find the real seed, consisting of a thin skin, with the plantlet, 

 embryo, completely filling it. Many seeds have within, besides the embryo, 

 a substance called albumen. The " chit " of a grain of maize is the em- 

 bryo : all else within the grain is albumen. The external surface of the 

 real seed in grasses is inseparable from the inner surface of the fruit. This 

 is the difference between the caryopsis of wheat and the achenium of the 

 compositae. The embryo of the sunflower is straight, with the rootlet 

 {radicle) pointing upwards. 



On the top of the achenium, and outside of the rest of the flower, are 

 two scales, easily rubbed off. These represent the free portion of the calyx, 

 and are called ih.e. pappus. There is an immense variety in the pappus of the 

 compositse. Often it remains after the corol falls off, and grows into a sail 

 to carry off the achenium. In the beggar-tick it consists of two stiff, barbed 

 bristles, by which the achenium is carried off on our clothes. 



Within or above the calyx is,. of course, the corol. This is less disguised 

 than the other parts have been. Its five petals are soldered into a tube, 

 with five points to show their number. This little organ alone is sufficient 

 to warrant the conjecture, that the compositae are an order of the monopeta- 

 lous exogens : that conjecture is correct. 



The androecium within consists of five stamens, with free filaments ; but 

 their anthers are connate into a tube. Connate anthers are also found in 

 lobeliate plants, and in a very few others. 



Of the gynoecium, the more important part is, of course, beneath the 

 apparent insertion of the corol and filaments. If it consist of two or three 

 carpels, the ovaries (being adnate to the outer organs) are, of course, con- 

 nate into one body. This has a single cavity, with a single erect seed. 

 The styles (if theoretically more than one) are connate nearly to their top. 

 Passing through the tube of anthers, the style divides into two branches. 

 The shape and character of these is of great artificial importance to help 

 find in what part of this immense order a plant belongs. 



