THE SENNA FAMILY 



C^SALPTNIACE^ Klotzsch & Garcke 



IJBOUT loo genera, containing looo species of trees, shrubs, herbs, and 

 vines, some of which are armed with very large, stout prickles, com- 

 pose the Senna Family. They occur throughout the warmer temperate 

 regions, but are most abundant in the tropics. The most important 

 economic products of this family, are Senna and Logwood, the former being the 

 leaves of several African species of Cassia; they are used for their laxative prop- 

 erties; this property is also possessed by many other species of the genus Cassia in 

 a lesser degree. Logwood is the heartwood of the trunk and roots of Hamatoxy- 

 lon campechianum Linnaeus, of the West Indies and Central America, and is to 

 this day the most important of the vegetable dyes, most of which have been dis- 

 placed by fhe products of synthetic chemistry. 



The leaves of the Senna family are mostly compound, but simple in a few 

 genera. The flowers are borne in various forms of clusters, seldom solitary, mostly 

 perfect, sometimes monoecious, dioecious, or polygamous, nearly regular or quite 

 irregular; the calyx consists of 5 more or less united sepals; coroUa usually of 5 

 petals, imbricated, the lower ones enclosing the upper one in the bud ; stamens 10, 

 sometimes fewer, their filaments distinct or partly united; ovary i-carpeled, i- to 

 many-seeded, usually sessile, but sometimes stalked, the style terminal. The fruit 

 is a legume, 2-valved, mostly dehiscent; seeds with or without endosperm. 

 The arborescent genera of our area are 



Flowers very irregular. 

 Leaves bipinnate; pod swollen, fleshy. 

 Leaves simgle; pod flat, papery. 

 Flowers nearly regular. 



Flowers dicecious or polygamous. 

 Pod flat, leathery; stamens longer than the small corolla. 

 Pod swollen, woody; stamens shorter than the large corolla. 

 Flowers perfect. 



Leaf with a short, spur-like petiole, ending in a spine, the axis of the 



pinnae broad and winged. 

 Leaf with a long petiole, the axis of the pinnae not broad nor winged. 

 Calj^-lobes valvate. 



Spiny; leaflets few; pod not over 10 cm. long. 

 Not spiny; leaflets many; pod over 20 cm. long. 

 Cal)^-lobes imbricated; pod small, very flat. 



Tamarindus. 

 Cercis. 



Gleditsia. 

 Gymnodadus. 



5. Parkinsonia. 



Cercidium. 



Delonix. 



Poinciana- 



533 



