312 Plants and their Ways in South Africa 



A. honida, W. (Karroo Thorn or Doornboom) has ivory-white thorns 

 (stipules). A. giraffae, Bch., has strong brown thorns. 



BB. Stamens connate. 



Albizzia. — Petals united ; stamens joined at base into a 

 tube ; leaves bipinnate with glands ; unarmed. Flowers in 

 heads or spikes with long white, rosy, or purple feathery 

 clusters of stamens. Two South African species. 



Zygia, found in Natal, has a longer staminal tube than 

 Albizzia, 



AA. Stamens lo; pollen powdery. 



Htltada has spicate flowers ; the margined fruit breaks 

 transversely into i -seeded parts. Shrubs, mostly climbing by 

 tendrils (terminal pinnae) or by hooked prickles. 



Elephantorhiza (Eland's boontjes) is a small glabrous 

 shrub with very large roots. Legume dehiscing by valves 

 separating from the margins continuous. Leaves bi-pinnate ; 

 flowers in dense spike-like racemes. 



Sub-tribe C^salpine^e. 



Cassia. — Flowers nearly regular, yellow. Stamens lo, or 

 the 3 upper wanting. In some the lower anthers are longer, 



Fig. 285. — Cassia arachoides , Bur. Vertical section of flower : sa, large 

 stamens ; sb^ small stamens ; sc, staminodes. (From Edmonds and Marloth's 

 " Elementary Botany for South Africa".) 



and open by terminal pores. These brush against the insect's 

 body while it is eating pollen from the upper ones. The 



