igo THE STORY OF PLANT LIFE 



refer to the character of the perianth, or the number 

 of whorls. In the former there is but one, the calyx 

 generally speaking ; in the latter there is no perianth 

 as a rule. But in the former group Euphorbia is 

 included, and in this there is no perianth. 



The Monochlamydeae include orders in which the 

 flowers are not in catkins. The perianth is single 

 and inferior. Here are included : 



(i) Illecebraceae. (5) Elaeagnacese. 



(2) Chenopodiaceae. (6) Euphorbiacege. 



(3) Polygonaceae. (7) Urticaceae. 



(4) Thymelaeacese. (8) Ceratophyllaceae. 

 In Nos. I, 3, 4 the flowers are bisexual. In 2, 5 



and 7 they may be unisexual or bisexual. In 6 and 

 8 they are unisexual. 



The other section embraces plants with flowers not 

 in catkins, and with a single, superior perianth, e. g. 

 Loranthaceae, Santalacese, and Aristolochiacese. 



In the case of the Achlamydeae both calyx and 

 corolla are wanting except in Cupuliferae. The flowers 

 are also unisexual, the males in catkins, the females 

 in spikes or catkins. There may be a perianth or it 

 may be wanting. In the Myricaceae the flowers are 

 of both sexes and there is no perianth. The plants 

 are monodioecious in the Cupuliferae and there are 

 no sepals, or five or more. In the Salicaceae the 

 plant is dioecious and both of the sexes are in catkins. 



None of the members of this group possess albumen 

 in the seeds. In Myricaceae and Salicaceae the ovary 

 is one-celled, in Cupuliferae two- to three-celled. 



