368 



THE HIGHER DICOTYLEDONS. 



STIGMA 



In an open flower (Fig. 152) note the narrow strap-like 

 outgrowth from the outer side of the mouth of the corolla- 

 tube. How many teeth are there at the top of the strap ? 

 Now examine the flower carefully with your lens. Note the 

 slender style, divided at the top into two curled branches 

 (stigmatic arms), each about 2 mm. (^ inch) long, with 

 short hairs (in about 12 rows) on the inner (stigmatic) 

 surface ; note the long hairs on the style a little below the 

 point of branching. Slit down the corolla-tube and trace 

 the style down to the bottom of the tube; on its way 



down, the style passes through 

 a tube about J inch long ; holding 

 the top of the style, pull it out 

 of this narrow tube. 



What is this tube around the 

 style? Can you see five slender 

 threads joining the lower edge of 

 this tube to the inner surface of 

 the corolla-tube ? If so, you 

 should be able to see that the tube 

 consists of the five anthers joined 

 together by their sides ; their out- 

 lines can, however, be seen on 

 careful inspection. 



What is the swelling below the 

 base of the corolla-tube ? Note 

 the hairs which form a circle just 

 above this swelling. Can you see 

 a slender neck-like part between 

 the swelling (ovary) and the ring 

 of hairs (pappus, representing the 

 calyx) ? Can you see the small 



Fig. 152. Flower of Dandelion, vino- liVp pneliinn fnppfarv^ at tTiP 

 lower part (corolla-tube and gp-llie CUSniOn (nQG^TJ) at tne 



ovary) cut open. bottom of the corolla-tube, around 



the base of the style ? If you 



cannot make out all these points in the structure of the flower 

 at the first try, examine more flowers until you succeed in 

 seeing all the parts. The honey rises in the narrow corolla- 

 tube, so that even short-tongued insects can reach it. The 

 heads are visited by an unusually large variety of insects, 

 including hire-bees, humble-bees, flies, beetles, and butterflies, 



ANTHERS 



-COROLLA 



-STYLE 



PAPPUS 



^NECTARY 

 OVARY 



