152 



GROWTH AND WORK OF PLANTS 



terminal flowers on all the branches reach nearly the same 

 height as the terminal flower on the main shoot, forming a 

 somewhat flattened or convex top of the flower cluster. This is 

 illustrated in the basswood flower. Where the flower cluster is 

 quite large and the branching quite extensive, compound cymes 

 are formed, as in the dogwood, hydrangea, etc. 



2. The helicoid cyme. Where successive lateral branching 

 takes place, and always continues on the same side, a curved 

 flower cluster is formed, as in the forget-me-not and most 

 members of the borage family. This is known as a helicoid 

 cyme (fig. in). Each new branch becomes in turn the 

 "false" axis bearing a new branch on the same side. 



3. The scorpioid cyme. A scorpioid cyme (fig. no) is 

 formed where each new branch arises on alternate sides of the 

 "false" axis. 



SUMMARY OF THE FLOWER. 



Parts 

 of the 

 flower. 



Kinds of 

 flowers. 



Floral envelopes 



Essential parts 



/ Calyx, made up of sepals. 

 } Corolla, made up of petals. 



f Filament or stalk. 



Stamens -| Anther (with locules which 

 [ contain pollen). 



Ovary (with ovules). 

 Pistils Style. 



Stigma. 



Simple pistil = i carpel. 

 Compound pistil = 2 or more carpels. 



Complete flower, all four series of parts are present. 



Incomplete flower, when one or more series of parts are absent. 



Apetalous flowers, petals absent. 



Naked flowers, both floral envelopes absent. 



Perfect flowers, stamens and pistils both present. 



f Staminate flowers, stamens present, pis- 



, a I tils absent. 



Imperfect flowers < 



| Pistillate flowers, pistils present, stamens 



[ absent. 



Neutral or sterile flowers, stamens and pistils both absent or 

 rudimentary. 



