FAMILIES OF FLOWERING PLANTS. 



65 



bous, while those of the epiphytes are fibrous and wiry, enabling 

 them to become firmly attached to the support. The leaves are sheath- 

 ing at base, often fleshy, occasionally reduced to scales. The flowers 

 are very generally conspicuous and handsomely colored; even when 

 small and of dull hues their beauty of form attracts attention. 



In order to discuss floral structure in the orchids it will be neces- 

 sary to explain a number of terms which are in use to indicate special 

 modifications of the perianth, stamens and pistil. The perianth con- 



FlG. 55.— The yellow liidy's slipper {Vi/pripeflimn hirsutum) a 

 native orchid. (From Macmillan's Minnesota Plant Life, by 

 courtesy of the author). 



sists of six parts or segments in two series of three each: the outer 

 series or sepals are usuajly similar or nearly so in shape and coloration. 

 The two lateral segments of the inner series, or petals, are also alike; 

 but the third inner one, known as the ///>, is widely dissimilar in shape 

 and is often the most conspicuous part of the flower. The one or two 

 stamens and style are entirely consolidated into a body known as the 

 column; this bears one or two 2-ceIled anthers, the pollen of which is 

 not of the ordinary sort, but is united by elastic threads into several 

 stalked waxy masses caWed j)ollmia, attached at the base by a viscid 



