224 MANUAL OF BOTANY 



Class XI.— DICOTYLEDONES. 



The plants comprised in this group are usually now divided 

 into three sub -classes as under : — 



Sub-Class I. — MONOCHLAMYDE^. 



The flowers have never more than a single whorl of perianth 

 leaves, which may be petaloid or sepaloid. Very frequently there 

 is no perianth. The flowers are very frequently unisexual. 

 Bentham and Hooker, in the ' Genera Plantarum,' divide them 

 further into eight series, each comprising several Natural Orders 

 as under :— 



Series 1. — CurvemhryecE. * 



Character s. — Endosperm frequently farinaceous. Embryo 

 curved, eccentric, lateral or peripheral, rarely straight. Ovules 

 most frequently 1 in the ovary or 1 in each loculus. Flowers ^ , 

 or in some genera unisexual or polygamous. Petals very rare ; 

 stamens equal in number to the segments of the perianth ; rarely 

 fewer or more. 



Order 1. Nyctagineae. 



2. Amarantaceae. 



3. Chenopodiaceae. 



4. Basellaceae. 



5. Phytolaccaceae. 



6. Petiveriaceae. 



7. Batidaceae. 



8. Polygonaceae. 



Series 2. — Multiovulatce aquaticce. 



Characters. — Aquatic herbs, submerged. Ovary syncar- 

 pous, ovules numerous in each loculus or on each placenta. 

 Order 9. — Podostemacece. 



Series 3. — Multiovulatce terrestres. 



Characters. — Terrestrial trees or shrubs. Ovary syncar- 

 pous ; ovules numerous in each loculus or on each placenta. 

 Order 10. Nepenthaceae. 



11. Cytinaceae. 



12. Rafflesiaceae. 



13. Aristolochiaceae. 



