STRUCTURE OF ORCHID FLOWERS 
A short note on the structure of flowers and fruits was 
given in the first two booklets of this series, but orchid 
flowers differ considerably from the ordinary flower. There 
are three sepals, which are usually coloured and like petals. 
The petals are also three in number, the two side ones 
being like the sepals, but the third usually very different in 
shape and complicated in structure, called the lip. The 
stamens and style are not separate but have become united 
into a column in the centre of the flower, arising from 
the base of the lip. At the top of the column is the single 
stamen, with the pollen aggregated into one or several 
masses called poll inia, so arranged that they are easily with- 
drawn by an insect visiting the flower, to whose body they 
stick and are so carried to another flower, where they are 
transferred to a sticky hollow immediately below the 
stamen, which is the stigma. The accompanying drawing 
of a Spathoglottis flower and its column show's these parts. 
The ovary in the orchid flower is contained in the stalk 
immediately below the flower. After pollination it swells 
up into a capsule, which, when it is ripe, opens by three 
slits to allow the innumerable, tiny, dust-like seeds to be 
scattered by the wind. 
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