I30 MORPHOLOGY 



of A. Bees flying from flower to flower, some young 

 and some old, must cross-pollinate them. 



In Pedilanihus tithymaloides (rang-chita) the flowers 

 are protogynous. The honey is secreted at the heel- 

 like portion of the involucre. A bee alighting upon 

 an older flower with ripe stamens (fig. 1 14, a), while 

 busy sucking the honey, becomes coated with pollen. 

 Should it next visit a younger flower with ripe pistil 

 (fig. 114, b), pollination will be effected, for the ripe 

 pistil of a younger flower occupies the exact position 



...St 



Fig:. 114. — Rang-ch'ita. {Pedilanihus tiihymaloides) 



A, s. Ripe stamens; si, ripe drooping stignaa (cyathium). B, s. Young stamens; 

 si, ripe stigma. 



of the ripe stamens of an older one. The flowers of 

 this plant appear before the leaves, and they are 

 conspicuous because of this and of their scarlet-re^ 

 involucre. 



7. Butterfly- and Moth-flowers. — In these the 

 nectar is concealed in deep narrow tubes or spurs. 

 The butterfly-flowers are usually red, moth-flowers 

 are white. The more deeply the honey is concealed 

 the more exclusively is it secured by butterflies. 

 Many butterfly-flowers are distinguished by an agree- 

 able and often very powerful odour. Moth-flowers, 

 as stated above, are white and devoid of nectar- 

 guides, and possess an odour that is frequently very 

 powerful, and capable of being perceived from a great 



