128 Shaw — Structure of the Flowers in 



The axis bearing the evident flowers is rather sharply three- 

 angled and slightly winged. In the phloem the indurated 

 layer forms a nearly continuous ring. 



The axis bearing the aerial cleistogamic flowers is smaller 

 in diameter and faintly three-angled, two angles being more or 

 less winged. The induration of the phloem is not so great. 



The axis bearing the subterranean cleistogamic flowers is 

 variable in size, but averages considerably larger than the 

 preceding. It is elliptical in section, and there is scarcely 

 any induration in the phloem. The cortical parenchym is 

 very loose and spongy, and the external cuticle only faintly 

 formed. Sometimes the medulla is almost obliterated, and the 

 wood then appears as a central strand. 



Bracts. — Small bracts are present in the evident raceme, but 

 they fall away about the time of flowering. In the racemes 

 of both sorts of cleistogamic flowers, they are persistent as 

 small scales. 



Calyx. — A. The Chasmogamic Flower. In this the three 

 outer sepals are small, green, i ^-2 millimeters long, ^— i 

 millimeter wide. The two inner sepals or wings are large, 

 pink-purple, and projecting beyond the corolla and stamens 

 enclose these inner members. The posterior one is slightly 

 larger. Referring for a moment to the foliage leaf, its epi- 

 dermis is composed of cells with wavy outlines and peculiarly 

 thickened walls, as shown in Plate XVII, Fig 10. Stomata 

 are found over both surfaces. In comparison with the foliage 

 leaf both upper and lower epidermis of the three outer sepals 

 consist of wavy-walled cells, rather like those of the lower 

 leaf epidermis, but more elongated. The walls, perpendic- 

 ular to the surface, have not the peculiar, inwardly projecting 

 thickenings of the former. The outer epidermis is well 

 supplied with stomata, especially in the middle region. On 

 the inner surface the stomata are rare. 



