448 BOTANY 



Suborder Halorrhagidinese 

 Endosperm present, aquatics fam. 1. Halorrhagidaceae 



Suborder Cynomoriinese 

 fam. 1. Cynomoriacese 



Order XIII. Umbelliflorae 



Berry or Drupe f fam. 1. Araliaceae 



Schizocarp -j " 2. Umbelliferse 



Drupe I " 3. Cornaceae 



SERIES III. SYMPETALAE (METACHLAMYDE^) 



The Sympetalae are, as a whole, the most specialized of the Dicoty- 

 ledons, and therefore stand at the head of the vegetable kingdom. 

 While the number of species is much greater than that of the Chori- 

 petalae, they are much more uniform in type, and there are fewer 

 orders and families. 



The most characteristic feature is the marked sympetaly of all but 

 a very small number of them. While a small number, like Mono- 

 tropa and Clethra, have the petals nearly or quite free, in most of 

 them the corolla is tubular or cup-shaped. 



In none of the Sympetalse is the number of stamens more than 

 twice that of the corolla-segments, and frequently the number of sta- 

 mens is less than the corolla-lobes,' due to a suppression of one or 

 more of them. This reduction in the number of stamens is usually 

 combined with another indication of specialization ; i.e. very marked 

 zygomorphy. 



Both hypogynous and epigynous flowers are met with. In some 

 of the simpler types (Ericaceae, Primulaceae) the carpels equal in 

 number the petals, and these forms are sometimes known as the 

 " Isocarpae," in distinction from the " Anisocarpae," in which the 

 number of carpels is less than the petals. 



The Sympetalae are especially developed in the Tropics, where 

 many of them become trees. Relatively few of them attain tree- 

 like proportions in more temperate regions. Of native trees belong- 

 ing to the Sympetalae, may be mentioned species of Catalpa, Arbutus, 

 Arctostaphylos, Diospyros, and Fraxinus. 



Whether the Sympetalae form a homogeneous group, or whether 

 sympetaly has been developed in more than one series, is not cer- 

 tain. It has been suggested that the isocarpous forms constitute 

 one series, perhaps related to the Centrospermae, and that from these 

 have been derived the Tubiflorae. A second series, derived from the 

 Umbelliflorae, is assumed to have given rise to the Rubiales and 

 Campanulatae. 



