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 lobes 

 with the broad 

 sessile bases, 

 sepaZs; 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, spathes ; s, sepals + p, 

 petals = perianth. 



- 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. 2 9 2 . — Vertical 

 section of iris flower, with 

 perianth removed, showing 

 a stamen and three stig- 

 mas: «/, stigmatic surface. 



Fig. 293. — Cross sec- 

 tion of ovary of iris flower : 

 c, c, carpels ; /, /, locules ; 

 Oil, ovules ; pi, placenta. 



