ADAPTATIONS FOIl DISPERSAL OF IRUIT & SEEDS 24-0 



ripe, the outer tissues of the style (Ivy causing it to curl 

 up rapidl}' which has the effect of violently ejecting the 

 seed. In the allied genus Pelargonium the fruit is similar 

 but the ovary is not split. AVhen the 5 carpels are ripe 

 they separate suddenly and are thrown some little 

 distance from the plant. 



(c ) This class of fruit really belongs to the first section 

 enumerated above, but as it is characteristic of many 

 Lcgitiiiinosac it can conveniently be considered by itself. 

 In species of I ud if/of era, Tephrosia^ Crotalaria, etc., the 

 pod when ripe is in a state of tension and may suddenly 

 burst, in doing so the two halves undergo a spiral tortion 

 which is ver}' rapid and results in the seeds being 

 scattered. (PL III. fig. 8.) 



The writer recently came across an interesting case of 

 seed dispersal which appeared to combine various 

 methods for securing this end. The plant is Barleria 

 thiinhergiana (Acanthaceae) PL III., figs. 3, 4, 5, 6, 7, and 

 was found growing at Glen, in the Orange Free State. 

 In habit the plant is prostrate ; the fruiting inflorescence 

 is about the size of a small hen's eg^ and of the same 

 shape. The bracts of the infloreifcence are spiny and it 

 is quite conceivable that they could be carried away by 

 adhering to the legs of sheep or cattle. AVlien the in- 

 florescence breaks up we find that each fruit is enclosed 

 between two large membranous bracts which would 

 enable the fruits to be scattered over the veld by the w^ind 

 away from the place where the inflorescence fell to pieces. 

 The fruits are hygroscopic and when they absorb water 

 they suddenly explode expelling the seeds. Measure- 

 ments made, showed that the seeds were scattered over 

 a radius of at least 11 ft. Tightly covering the seeds 

 are a number of long hairs which when wetted uncurl 

 and stand out and thus attach the seed to the piece of 

 ground which is Avet and most suited to the germination 

 of the seed. 



