226 



NATURAL HISTORY OF PLANTS. 



the bud, and sometimes accompanied by two very small lateral 

 petals. The androceum consists of an indefinite number (often 

 very large) of decimate hypogynous or nearly hypogynous stamens, 

 composed of free or shortly coherent filaments, and introrse two- 

 celled anthers of longitudinal dehiscence. Sometimes the stamens 

 are all of nearly equal size, both in filament and anther ; sometimes 

 on the contrary, those next the standard are shorter than those on 

 the opposite side of the flower, while some of these last may 

 assume considerable dimensions, both anther and filament being at 

 once longer and thicker. The free superior gymeceum consists of 

 one, or more rarely of two, carpels (figs. 203, 204). The ovary 



Tuvnatea microstyles. 



"*^v &>-■ Jff r '^^ ■' S ■' ' *".•'■ 



Fig. 203. 

 Flower ('f). 



Fig. 204. 

 Longitudinal section of flower. 



is stipitate, often bowed ; it contains an indefinite number of de- 

 scending ovules whose micropyles look upwards and outwards, and 

 it tapers above into an acute style whose undilated or slightly 

 capitate apex is covered with stigmatic papilla?. The pod is ovoidal 

 or elongated, cylindrical or turgid, indehiscent or bivalve. It contains 

 an indefinite number of arillate or exarillate seeds whose coats en- 

 fold an embryo, sometimes accompanied by albumen, which has 

 thick cotyledons and a short inflexed radicle. Tounatea comprises 

 unarmed trees from tropical America; one species alone has been 

 found in Africa. The leaves are alternate, imparipinnate or 

 unifoliolate, and possess two small or leafy lateral stipules. The 

 flowers are solitary or grouped into single or fascicled racemes, inserted 

 on the nodes of the old wood, or rarefy axillary to the living 

 branches, but pretty frequently forming ramified racemes, the leaves 

 of the branches being replaced by bracts. These last are usually 

 small and very caducous, and the flower is accompanied by two 



