THE BOOK OF THE IRIS 



PART I 

 CHAPTER I 



STRUCTURE AND NATURAL HISTORY OF THE 

 IRIS FLOWER 



ALL plants of the natural order Iridaceae have the ovary 

 below the perianth of the flower ; they have seeds which, 

 in addition to the germ, contain a horny food substance 

 known as endosperm, and they have three stamens with 

 extrorse anthers. These features alone serve to distin- 

 guish an Irid from all other monocotyledons, 1 but in an 

 Iris we must also find that the style branches are opposite 

 the stamens and the outer segments of the perianth, that 

 the style branches are furnished with crests and have 

 transverse stigmas, that the perianth (almost always) 

 has a tube above the ovary, and that the stamens are not 

 joined together. And further we may notice that Irises 

 are native only of the North Temperate Zone head- 

 quarters being found probably in Central Asia. 



Let us examine the flower of an Iris in greater detail. 

 On cutting across the ovary we find that it has three 

 cells and that the ovules are attached in the inner angle 

 of each cell (except only in Iris tuberosa, which has 



1 Plants which have one cotyledon, floral whorls in threes, leaves 

 with parallel veins, etc. one of the two great classes of flowering 

 plants. 



