MORPHOLOGY 



seeds of the aerial open flowers are either wholly 

 infertile or at any rate rarely fertile. Arachis hypogcea, 

 known in Bengali as chiner-badam or mat-kalai, also 

 bears cleistogamous flowers in addition to the ordi- 

 nary bright-yellow open flowers. Kantal, the Jack- 

 fruit tree of Bengal, is 

 known to produce un- 

 derground big Jack- 

 fruits which ripen under 

 the ground and bear 

 fertile seeds. When 

 ;he fruits are ripe the 

 ground under which 

 they lie opens and the 

 characteristic smell of 

 ripe fruits is emitted 

 through the opening. 

 Generally they lie so 

 deep that they have to 

 be dug out. The male 

 and the female spikes 

 on the aerial parts of 

 the stem are well 

 known, and it is also 

 well known that the 

 female spikes give rise 

 to ordinary Jack-fruits. 

 How the underground female spikes are pollinated is 

 a mystery, but that they produce fruits with fertile 

 seeds is a matter of common knowledge. Par- 

 thenogenesis, or the production of fertile seeds 

 without pollination and fertilization, is not unknown 

 among plants, so that the fertile underground fruits 

 may be an instance of parthenogenesis, or the result 

 of occasional cleistogamous bisexual flowers. Such 



Fig^. 103. — Dholapata or Jata-kanshira 

 {Commelinn benghaleiisis) 



o.f.t Open flowers above ground, c.f., 

 Cleistogamous flowers underground. 



