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 ternis which are in use to indicate special 
modifications of the perianth, stamens and pistil. The perianth con- 
e 
Fic. 55.—The yellow lady's slipper (Cypripedium hirsutum) a 
native orchid. (From Macmillan’s Mignesota 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 usually 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 Jp, is widely dissimilar in shape 
and is often the most conspicnous 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-celled anthers, the pollen of which is 
not of the ordinary sort, but is united by elastic threads into several 
stalked waxy masses called pollinia, attached at the base by a viscid 
