206 



THE FLOWER 



indicate the position of the two outer stamens, and a cross 

 before the other two to show where stamens are wanting 

 to complete the symmetry of this set as in the diagram 

 (Fig. 395). When parts necessary to complete the plan 

 of a flower are wanting, as in this case, they are said to 

 be obsolete, suppressed, or aborted. Place dots before the 

 petals to represent the other four stamens. 



Examine the anthers under the lens. Are they extrorse 

 or introrse? What is their mode of attachment to the 

 filament ? (Sec. 284.) Sketch one of the anthers, show- 





394 395 



393-396- A cruciferous flower : 393, side view. 394, view from above. 395, 

 diagram of parts: p, petals; s, sepals; st, stamens; pi, pistil; cl, claw of petal ; 

 +, +, position of the missing stamens. 396, pistil and stamens, enlarged (GRAY) . 



ing the sagittate base. Remove all the stamens and 

 sketch the pistil, showing the long, slender ovary, the very 

 short style, and the capitate (round and knoblike) stigma. 

 Compare the pistil with a more matured one from an older 

 flower lower down on the stem, and with the descriptions 

 of dehiscent fruits in Sections 93-109, and decide to which 

 kind it belongs. Represent its position by a small circle, 

 in the center of your sketch of the separate parts. You 

 have now a complete ground plan of the flower. To what 

 form of leaf arrangement does it correspond ? Diagram 

 a vertical section showing the position of the ovary with 



