OUTLINES OF BOTANY. XXV 



or such, of them as are present, are capable of performing their several 

 functions. Therefore, properly speaking, an incomplete flower is one in 

 which any one or more of these organs is wanting ; and an imperfect flower, 

 one in which any one or more of these organs is so altered as to be in- 

 capable of properly performing its functions. These imperfect organs are 

 said to be abortive if much reduced in size or efficiency, rudimentary if so 

 much so as to be scarcely perceptible. But, in many works, the term in- 

 complete is specially applied to those flowers in which the perianth is simple 

 or wanting, and imperfect to those in which either the stamens or pistil are 

 imperfect or wanting. 



85. A Flower is 



dichlamydeous, when the perianth is double, both calyx and corolla 

 being present and distinct. 



monochlamydeous, when the perianth is single, whether by the union 

 of the calyx and corolla, or the deficiency of either. 



asepalous, when there is no calyx. 



apetalous, when there is no corolla. 



naked, when there is no perianth at all. 



hermaphrodite or bisexual, when both stamens and pistil are present 

 and perfect. 



male or staminate, when there are one or more stamens, but either no 

 pistil at all or an imperfect one. 



female or pistillate, when there is a pistil, but either no stamens at 

 all, or only imperfect ones. 



neuter, when both stamens and pistil are imperfect or wanting. 



barren or sterile, when from any cause it produces no seed. 



fertile, when it does produce seed. In some works the terms barren, 

 fertile, and perfect are also used respectively as synonyms of male, female, 

 and hermaphrodite. 



86. The flowers of a plant or species are said collectively to be unisexual 

 or diclinous when the flowers are all either male or female. 



monoecious, when the male and female flowers are distinct, but on the 

 same plant. 



dioecious, when the male and female flowers are on distinct plants. 



polygamous, when there are male, female, and hermaphrodite flowers 

 on the same or on distinct plants. 



87. A head of flowers is heterogamous when male, female, hermaphrodite, 

 and neuter flowers, or any two or three of them, are included in one head ; 

 homogamous, when all the flowers included in one head are alike in this 

 respect. A spike or head of flowers is androgynous when male and female 

 flowers are mixed in it. These terms are only used in the case of very few 

 Natural Orders. 



88. As the scales of buds are leaves undeveloped or reduced in size and 

 altered in shape and consistence, and bracts are leaves likewise reduced in 

 size, and occasionally altered in colour ; so the parts of the flower are 

 considered as leaves still further altered in shape, colour, and arrangement 

 round the axis, and often more or leas combined with each other. The 

 details of this theory constitute the comparatively modern branch of Botany 

 called Vegetable Metamorphosis, or Homology, sometimes improperly termed 

 Morphology (8). 



89. To understand the arrangement of the floral parts, let us take a com- 

 vlete flower, in which moreover all the parts are free from each other, definite 



