AMERICAN WILD FLOWERS 471 



on our southwestern deserts is the century plant (fig. 287) or 

 FALSE SISAL from whose basal rosette of pointed succulent leaves, 

 thicker than those of a yucca, rises a flowering stalk often ten feet 

 in height, terminated by a cluster of bright yellow flowers. 



The Iris Family 



The Iris Family {Iridaceae) is also a close relative of the Lily 

 Family, with flowers similar to those of the Amaryllis family but 

 with three stamens instead of six. Blue flag or wild Iris is 

 found in wet places throughout the entire United States; above 

 its long slender leaves arise the clusters of showy flowers with 

 recurved sepals and erect petals. Other species have yellowish 

 brown flowers or yellow flowers marked with lavender. Blue- 

 eyed GRASS is a smaller member of the family, with grass-like 

 leaves and smaller purplish blue flowers with spreading petals 

 and sepals. 



The Orchid Family 



The Orchid Family {Orchidaceae) represents the culmination 

 of floral evolution in the Monocots just as the thistle family does 

 for the Dicots. The family consists of some ten thousand species 

 most of which are tropical epiphytes; the temperate species which 

 include most of our native orchids are terrestrial plants of forests 

 and woodlands. The orchid flower (fig. 288) is very complex as 

 a result of specialization for insect pollination; it is characterized 

 by three sepals — often colored, and resembling petals — and 

 three petals, one of which forms a conspicuous lip which assumes 

 a variety of shapes. 



Lady's slippers can be recognized by the sac-like lip of the 

 flower. The most familiar species, with basal oval leaves, include 

 the moccasin flower of our northeastern woods and bogs; 

 each flower consists of narrow purplish sepals and two narrow 

 brown petals with pink sac-like lip. Other lady's slippers are 

 yellow, white or colorfully striped. The California lady's 

 SLIPPER found along the northern Pacific coast has yellowish 

 green flowers with white lips. 



In some genera of the Orchid Family the lip is lobed or 

 fringed. The round-leaved orchis of our northern states has 



