Classification of Plants 157 



incomplete as their descendants have remained up to the 

 present time. Later flowers. Uke Protea had a simple perianth. 

 When plants attained complete flowers the parts were at first 

 distinct, as in the Anemone family (Ranunculacese). 



As flowers developed along with insects, parts combined in 

 various ways. A gamopetalous corolla gave a firmer support 

 to the winged guest. If a tubular flower hangs obliquely, the 

 fact of visiting insects always lighting on the same place might 

 account for the irregularity of the blossom. Parts of the flower 

 became developed into cunningly devised nectar cups or for 

 some other special purpose, as, for example, in the calyx of 

 Compositae. 



In learning to distinguish plants, it greatly simplifies matters 

 to be able to group those which seem to be related ; but we 

 must remember that outward appearance is often deceitful, and 

 that plants, like people living under the same conditions, come 

 to clothe themselves alike. 



A Protea is taken for a cactus by a stranger, but it would 

 be hard to find a common ancestor for these two families. 

 The first thing to be learnt is the conspicuous characters of the 

 larger groups of families. 



In classifying a plant, a key is useful for identifying the 

 genus to which it belongs. After a little practice the order or 

 family characters will be recognized at a glance without the 

 key. 



Key for determining the Orders. 



The orders of flowering plants in this key are arranged 

 after the system of Bentham and Hooker, which is used in the 

 " Genera of South African Plants " and in " Flora Capensis." 



DICOTYLEDONS. 



Group i. — Polypetalcz. 



Sub-class I. — Thalamiflor^. 



Sepals usually separate, free from the ovary. 

 Ovary superior. 

 A. Carpels separate ; stamens many . . RanunculacE/E. 



