460 DR. M. T. MASTERS ON THE SUPERPOSED 



It is doubtful whether or not some Sauvagesiacese should be 

 included under this category**. In Salvertia convalliodora the 

 staminodes are superposed to the petals and in Hawsonia, accord- 

 ing to Harvey, Thes. Cap. xxxi., the disposition is 



S 



P 



X 



Sts. 



If the calyx were pleiotaxic and its elements superposed, we 

 might get such a formula as 



S 



* 



s 

 p 



p, 



and so on. 



4. Stamens superposed to petals, of which the simplest arrange- 

 ment is 



S 



P 



St. 



This is met with in ffliamnus, Vitis, Thomasia, Hermannia, 

 Picramnia, JPicrolem?na, and a large number of plants of various 

 orders. In Platytheca there are two rows of stamens, the outer 

 anteposed to the petals, the inner to the sepals — a most unusual 



arrrangement. 





s 



p 



St 



St. 



- In Commersonia a similar disposition exists ; but the inner row 



of stamens is here represented by staminodes. 



In Nitraria we often meet with two stamens before each of the 



five petals thus 



S 



P 



St St 

 St, 



the double stamen being probably the result of lateral chorisis. 



•ee 



Brasil 



