THE ANGIOSPERMAE 



1301 



become covered with pollen which they later transfer to the stigma of 

 another flower. 



The very striking flowers of Strelitzia reginae (Musaceae) are enclosed 

 by a tough spathe and emerge from it in succession. Each flower has large 

 orange sepals and bright blue petals which make a very conspicuous colour 

 contrast. Two of the petals are long and are united into an arrow-shaped 

 structure, of which the two flanges overlap above, covering the six stamens 

 and the style, the stigma protruding at the distal end. The third petal is 

 short and dome-like and covers the entrance to the nectar (Fig. 1228). 

 The pollinator is a Honey Bird, Nectarina afra, which bears on its breast 

 the same brilliant colours as the flower. It alights on the united petals and 

 walks along the flanges. When bending down beneath the dome-shaped 

 petal it presses the flanges apart, so exposing the stamens and getting pollen 

 on its breast. The protruding stigma is touched first on alighting and receives 

 any pollen which may have been brought from another flower. Insects 

 visit Strelitzia, but are very unlikely to accomplish pollination. 



2. Indirect Bird Flowers 



As an example of this type we mav take the very remarkable flowers of 

 Marcgravia nepenthoides whose pollination is described by Belt in his 

 account of his wanderings in Nicaragua (Fig. 1229). M. nepenthoides is not 



Fig. 1229. — Marcgravia nepenthoides. A, Inflorescence with nectary 

 pouches and circle of pendent flowers. B, Flower bud. C, Young 

 flower with corolla cap dropping oflF. D, Older flower with stamens 

 nearly all gone and stigmas exposed. {Modified from Le Maout and 

 Decaisne.) 



