240 The Field Naturalist s Quarterly August 



special parts. A complete flower is composed of four 

 distinct whorls or series of organs, each having its own 

 particular part to play in the life of the plant. These 

 organs are the result of a special development from foliage 

 leaves, although some of them bear but little resemblance 

 to ordinary green leaves. Now and again we see what we 

 are pleased to call " sports " — flowers bearing green leaves 

 in the place of the usual sepals or petals, showing thereby 

 a tendency to return to the original leaf-form. 



The four series of organs of which the complete flower 

 consists are : — the calyx or protective whorl, composed of 

 usually green sepals ; the corolla or attractive whorl, 

 composed of usually coloured petals ; the stamens, con- 

 sisting of usually filaments and anthers ; and the pistil, 

 consisting of usually ovary, style, and stigma. These two 

 last are called the essential or reproductive whorls. We 

 use the word " usually " purposely, because there are 

 infinite variations from the typical forms and combinations. 

 The calyx encloses the rest of the flower, when in bud 

 protecting the reproductive organs from injury. The 

 petals are the attractive parts of the flower, being coloured 

 and often beautifully marked, spotted, streaked, or sweetly 

 scented ; or in many cases have all these qualities combined, 

 to attract flying insects, which are useful in carrying pollen 

 from flower to flower. The stamens are the male part of 

 the flower, producing in the anthers the pollen grains ; the 

 pistils being of the opposite sex, the receptive portion of 

 the reproductive whorls, bearing ovules, which after fertilisa- 

 tion, become, under favourable conditions, the seeds of the 

 plant. 



There are, however, flowers which discard certain of 

 these whorls, especially the petals or attractive whorl. The 

 calyx is seldom dispensed with. There are fixed reasons 

 why these certain parts are not produced. One reason is 

 that the flower may be provided with a calyx of coloured 

 sepals, which serves a double purpose ; or the flowers may 

 not require the services of insect visitants, relying on the 

 winds of heaven, as the agents by which their pollen may 

 be distributed ; or, again, the flower may be (but this is 

 rarely the case) self-pollinising. 



