Flowers and their Parts 



143 



valvate, that is, they just meet by their edges. If they over- 

 lap, the aestivation is imbricate. In Hibiscus and Oxalis the 

 petals so overlap that one edge of each is without and one 



Fig. 136. — Convolute aestivation of Oxalis (the sepals are imbricate). 

 (From Edmonds and Marloth's " Elementary Botany for South Africa.") 



within another. They are twisted or convolute. In Crassula 

 and Adenandra one is quite within the others and one overlaps 

 by both its edges. Which aestivation is more common ? 



Fig. 137. — Imbricate aestivation 

 of both sepals and petals. 

 (From Edmonds and Marloth's 

 ' ' Elementary Botany for South 

 Africa.") 



Fig. 138. — Plumbago. 

 Stamens, honey glands, 

 and pistil. (From Hens- 

 low's "South African 

 Flowering Plants".) 



Honey glands are the parts of flowers which secrete 

 nectar. In the Buttercup [Ranunculus) and Grewia a gland is 

 placed at the base of each petal. Geranium has a gland at 

 the base of each long stamen. These flowers are regular and 



