1 194 



A TEXTBOOK OF THEORETICAL BOTANY 



is detached from the receptacle and the three staminodes uncurl elasti- 

 cally, shooting out the fruit to a distance of several metres. 



Fig. ii68. — Partiassia palusiris, Hower 

 showing the five branched stami- 

 nodes. 



Parnassia palustris (Saxifragaceae) (Fig. 1168) has five extrorse stamens 

 in the outer whorl and five staminodes in the inner whorl, whose bases are 

 attached to the petals. These staminodes have solid nectar-secreting bases, 

 but the upper ends form a fan-shaped group of filaments (Fig. 1169), each 

 ending in a glistening yellow knob which looks like a nectary and attracts 

 flies by the appearance of nectar. They have also deceived botanists. 



Fig. 1 169. — Parnassia palustris. A, Fertile stamen. B, Staminode, dorsal view. 

 C, The same, ventral view. {After Arber.) 



All these cases are " normal " formations, that is to say they are constant 

 throughout whole species or genera, but very curious abnormalities also 

 sometimes turn up (Fig. 1170), especially carpelloid stamens which either 

 bear both anthers and ovules or ovules only. Such stamens are not uncom- 

 mon in Sempervhuni. 'I'hey are generally broadened, and the ovules are 

 marginal and fully exposed. Carpelloid stamens occurred epidemically in 



