i66o A TEXTBOOK OF THEORETICAL BOTANY 



valuable tropical tree not only on account of its fruits but also on account 

 of its beauty. It is indigenous to Africa, but has for long been widely 



Fig. 1 5 19. — Cassia acutifolia. Fruits (Senna pods). 



cultivated in the tropics. It is widely used as an ingredient in pickles and 

 chutneys. Haematoxylon campechianiim is a native of Central America and 

 the West Indies. The young foliage is red and thorns develop in the leaf 

 axils. The heart wood contains the substance haematoxylin and is used in 

 dyeing under the name of Logwood. We may also mention Hymenaea 

 courbaril, the Locust Wood; Copaifera publijiora, Purple Heart Wood; 

 Poinciana regia, Flamboyant Tree, which is often cultivated in warm 

 countries because of its magnificently striking red blossom. The Bird of 

 Paradise Flower, Caesalpinia gilUesii, is also grown all over the subtropics 

 for its yellow and crimson flowers. 



In Cercis siliquastriini (Fig. 1520) the flowers are typically papilionaceous 

 with a zygomorphic corolla, the lower anterior petals forming a large pair 

 enclosing the essential organs, while the posterior pair are reflexed and 



Fig. 1520. — Cercis siliquastrum. Judas Tree. Flowers arising 

 from one of the older branches. 



