278 A TEXT-BOOK OP BOTANY 



The families most likely to be confused with the lilies 

 are the Amaryllis Family (Amaryllidacece) and the Iris 

 Family (Iridacece), but in both of these the ovary is inferior 

 ( 138) and appears beneath the flower. Among the 

 amaryllis forms (those with six stamens) are narcissus 

 (including daffodils and jonquils), snowdrop, snowflake 

 (Fig. 220), tuberose, and certain so-called lilies. Among 

 the iris forms (those with three stamens) are iris (including 

 the various flags) (Fig. 242), crocus, and gladiolus. 



160*. Orchids. In number of species the Orchid Family 

 (Orchidacece) is the greatest family of the Monocotyledons; 

 but orchids are comparatively rare plants, not extensively 

 distributed, and ' often very much restricted. In actual 

 number of individual plants they are not to be compared 

 with the glasses, or even with the lilies. They are noted 

 for their remarkably irregular flowers, whose bizarre forms 

 and brilliant coloration are associated with insect visits. 

 In fact, the orchids may be said to have specialized in 

 adaptations to insects ( 147). They can always be recog- 

 nized among Monocotyledons by their inferior ovary and 

 by the remarkable modification of one of the petals (appar- 

 ently the lowest one), which always differs from the others 

 in size and form, and is called the lip. Sometimes the lip 

 is like an inflated pouch or sac, as in the lady-slipper 

 (Fig. 275); and often it develops a conspicuous hollow 

 spur (Fig. 243). The great display of the family is in the 

 tropics, and there many of them are perching plants ( 41). 

 The tropical forms are most prized as greenhouse plants, 

 and a good collection of orchids in bloom is exceedingly 

 attractive. 



Very little use has been made of orchids, the best known 

 useful product being vanilla, which is extracted from the 

 fruit of a climbing orchid native in Mexico. 



161. Other useful Monocotyledons. Two useful and 

 well-known Monocotyledons do not belong to any of these 



