THE FLOWER 



205 



which conceals the lower part of the flower. Remove the 



spathe and observe that the lower part of the perianth is 



. united into a long, narrow tube, from 



the top of which the sepals and petals 



extend as long, curving lobes. 

 222. Arrangement of parts. - 



Sketch the out- 

 side of the flower, 



labeling the ob- 

 long, three-lobed 



enlargement at 



the base, ovary; 



the prolongation 



above it, tube of 



the perianth; the 



three outer lobesr 



with the broad 



sessile bases, 



sepals; the others, 



with their bases 

 narrowed and bent inward, petals. Now turn the flower over 

 and sketch the inside, labeling the three large, petal-like expan- 

 sions in the center, 

 stigmas. Do you 

 see any stamens? 

 Remove one of 

 the sepals and 

 look under the 

 stigma ; what do 

 you find there ? 

 Notice the little 

 honey pockets at 

 the foot of the 

 stamen. Run the 



head of your pencil into them and see what would happen 

 to the head of an insect probing for honey. 



FIG. 290. Iris flower: 

 sp, spathcs ; s, sepals + p, 

 petals = perianth. 



FIG. 291. Vertical 

 section of iris flower: 

 ov, ovules ; pi, placenta ; 

 tu, tube of the perianth 

 inclosing the style ; sta, 

 stamen ; sti, stigma ; o, 

 ovary. (After GRAY.) 



FIG. 292. Vertical 

 section of iris flower, with 

 perianth removed, showing 

 a stamen and three stig- 

 mas: sw, stigmatic surface. 



FIG. 293. Cross sec- 

 tion of ovary of iris flower : 

 c, c, carpels ; I, I, locules ; 

 ov, ovules ; pi, placenta. 



