154 



GROWTH AND WORK OF PLANTS 



flowers in the height of flowering is always very conspicuous, 

 because the stamens and the stigmas of the flower project so far 

 above the corolla tube at this time, and then by shortening 



Fig. 114. 

 Tubular flowers of sunflower, showing details of flowering from left to right. 



become inconspicuous again (see figs. 114, 115). For the study 

 of the flower several disk flowers in different stages of flowering 

 should be separated from the disk for close examination. 



254:. The calyx. The calyx is very inconspicuous. The 

 ovary is inferior since the calyx is joined to its outer surface and 

 covers it. It is seen as a narrow wedge-shaped white body with 

 the rest of the flower borne on its apex. The calyx is manifest 

 here only as two small white awn-like lobes, or chaff, which are 

 opposite (sometimes there are rudiments of smaller ones between). 



255. The corolla. The tubular corolla is abruptly broadened 

 or inflated near the base. The apex is divided into five short 

 acute lobes which show that it is composed of five petals. Com- 

 pare this inflated portion of the corolla in tubular flowers of 

 different ages. 



256. The stamens. The stamens are joined together by the 

 edges of their anthers and are thus syngenesious. They are five 

 in number and attached by the filaments to the lower part of the 

 inflated portion of the corolla. The anthers thus form a tube 



