FAMILIES OF FLOWERING PLANTS. 5 



o})ment to some of the tlowerless plants, while the absence of dift'erenti- 

 atecl organs, such as well-niarke:! Howers or floral leaves, emphasizes 

 the same condition. 



The Gymnospermae include four orders, the Gnetales, Gycadales, 

 Ginkgoales and C')niferales or Goniferae, besides several fossil orders. 



ORDER ONETA1.es. (Fl<i. 2.) 



This group includes the single family Gnetaceae. The average 

 reader is not likely to meet with the plants comprised in the family. 

 Of the three genera, Gnetum, with 15 species, is native of tropical 



'-rom Coulter's •• Plant Relations." Copyright, 1899, hy D. Applet"! 



Fjg. 3.— a cultivated Cycad (family CycadacfPe) showing- the crown 

 of leaves and palm-like stem. 



South America and portions of the Old World; Ephedra, comprising 

 20 species, is found in Mexico, South America and Asia, a few species 

 reaching the extreme southwestern I'nited States, while Tumboa, a 

 genus of a single species, is restricted to a small area on the west coast 

 of Africa. Gnetaceous plants as a rule are shrubs, the leaves either 

 opposite or reduced to small scales. The Howers are borne in dense 

 spikes, and are dioecious, that is, the male and female sj)orophylls 

 occur on different plants. The floral envelope or perianth is small and 

 membranous or scaly in texture, bearing little resemblance to a flower 

 in the ordinary sense. There is great difference in habit; many 



