THE DOGBANE FAMILY 



81 



3. Pollination. — Between the two seed-vessels there is a 

 gland on each side which secrete nectar.- Only insects Avith 

 long tongues can get the nectar at the bottom of such long 

 flower-tubes. Such are certain night moths. They, in their 

 turn, have to pollinate the flowers. The anthers are inclined 

 over the flat top of the style and deposit their pollen there. 

 But this part of the style is not receptive. The only part in 

 which the style can receive pollen is the collar or seam of the 

 hourglass-like stigma, which is sticky. Now, there are five 

 little openings between the five an- 

 thers through which the insect must 

 stretch its tongue into the flower- 

 tube. While doing so, the tongue 

 brushes against the sticky sides of the 

 stigma and deposits there any pollen 

 that it may have brought from an- 

 other flower. When the insect draws 

 its tongue back out of the tube, 

 it touches the pollen-masses lying 

 loosely on the top of the stigma which 

 readily adhere to the sticky tongue. 

 Thus the pollen of one flower is 

 carried to the style of another, and 

 self-pollination is avoided. 



4. The Fruit consists of two erect and cylindrical follicles, 

 dehiscing each in its ventral suture. Seeds numerous and small. 



St. 



Fig. 81. — Longitudinal section of 



floral tube of Vinca. A. Anthers. 



0. Opening between anthers. 



St. Stiffma. 



Other Apocjniaceae. 



The Corrinda {Carissa spinarum; Kan. Garji, Korinda; Mai. 

 Karanta; Tarn. Kali; Tel. Kalivi) is a common shrub, with 

 milky juice, spreading branches and opposite, axillary, often 

 forked spines (representing metamorphosed branches). Stipules 

 minute, interpetiolar leaves subsessile, elliptic, entire, glabrous, 

 coriaceous. Flowers white, sometimes with a tinge of pink, 

 fragrant, in cymes. Parts of flowers similar to those in Vinca. 

 Fruit a two-seeded berry with a very sticky pulp, edible. 



6 



