90 



PLAN OF THK FLOWER. 



[lesson 13. 



(Fig. 176, 177) ; when tlie flowers are paid to be dicecioiis (from two 

 (ireek words iiieaiiiiig in two household.^). Or tlie two may occur 



on the same plant 



or the same stem, 



as in the Oak, 



Walnut, Nettle, 



and the Castor-oil 



Plant (Fig. 178); 



Avhen the flowers 



are said to be mO' 



ncecious (that is, in one household). A flower 



may, however, be perfect, that is, have both 



stamens and pi.stils, and yet be incomplete. 



2\2. lllCOlliplclC Flowers are those in which 

 one or both sorts of the floral envelopes, or 

 leaves of the blossom, are wanting. Some- 

 times only one sort is wanting, as in the 

 Castor-oil Plant (Fig. 178) and in the Anem- 

 "^ one (Fig. 179). In this case the missing 



«ort is always supposed to be the inner, that is, the corolla ; and 

 accordingly such flowers are said to be apetalous (meaning without 

 petals)'. Occasionally both the corolla and the calyx are wanting, 

 ■when the flower has no proper cover- 

 ings or floral envelopes at all. It is then 

 eaid to be naked, as in the Lizard's- 

 tail (Fig. 180), and in the Willow. 



243. Our two pattern flowers (Fig. 

 168, *74) are regular and symmetrical 

 (239). We commonly 

 expect this to be the 

 case in living things. 

 The corresponding 



parts of plants, like the limbs or members of ani- 

 mals, are generally alike, and the whole arrange- 

 ment is symmetrical. This symmetry pervades 

 the Hossoni, especially. But the student may often fail to perceive 



FIC 178. Moiifprioiis flowers, i. e. one slaiiiinritc (.«) and one pistillate (/)) flower, of 

 the C?itnr-oil Plant, growing on the same stem. 



FIG. 179. Apetalous (incomplete) flower of Anemone Pennsylvanica. 

 FIG. 180. A naked (but perfect) flmvcr of the Lizard's-lail. 



