Flowers and their Parts 



135 



one whorl of floral leaves. Although it may be showy, the 

 one whorl is usually called the calyx. If any one or more 

 whorls of the perianth are wanting, the flower is incomplete. 



After a few weeks the Clematis loses its sepals, and only 

 the seed-forming portion remains. The ovules within tlie 

 ovary cannot become seeds without the pollen from the 

 stamens ; so the stamens and pistils are called the essential 

 organs. 



If the anthers are removed from any flower before they 

 shed their pollen, and the flower is then covered or removed 

 from any similar flower, the ovaries will wither away and form 

 no seed. If, after the stamens were removed, pollen were 



Fig. 123. — Lcucospcnnum ellipticum, L., has no corolla. The flower 

 is incomplete. (From Edmonds and Marloth's "Elementary Botany for South 

 Africa". ) 



brought from a similar flower and placed at the right time on 



the stigma, the pistil would continue growing, and seeds would 



be formed as though there had been no disturbance, even 



though the petals and sepals were removed. A perfect flower 



has both stamens and pistils. In the flowers which bear the 



seed in the Silver Tree, mealie, or Montinia stamens are 



wanting, while those that have stamens produce no seed. 



Flowers in which either set of essential organs is wanting are 



imperfect. If the pistils are wanting, the flowers are sta- 



minate. If the stamens are absent, the flowers are pistillate 



or fertile. A perfect flower is sometimes called bisexual or 



