STRUCTURAL BOTANY. 



[38, 39. 



of two united sepals, as indicated by the two teeth at 

 the top (79). 



108. Glumes and pales represent the floral en- 

 velopes, or rather the involucre 



of the Grasses (436). Their al- 

 ternating arrangement clearly 

 distinguishes them from a peri- 

 anth. 



109. The duration of the 

 calyx and corolla varies widely, 

 and is marked by certain gen- 

 eral terms. It is caducous 

 when it falls off immediatelv, 



78, Flower of Scirpus lacustris, magni- 

 aS the CalyX Of Poppy, CO- fied ? consisting of six seta?, three stamens, 



rolla of Grape ; deciduous 

 when it falls with the stamens, 

 as in most plants; and per- 

 sistent, if it remain until the fruit ripens, as the calyx 

 of Apple. If it continue to grow after flowering, it is 

 accrescent; and if it wither without falling off, it is 

 marescent 



78 



three pistils united, except the stigmas. 

 79, Flower of Carex rivularis Q , with g, 

 its glume, p, its bottle-shaped perigynium, 

 2-toothed at top, enveloping the triple 

 ovary ; stigmas, three. 



X 



CHAPTER VII. 



OF THE ESSENTIAL ORGANS. THE STAMENS. 



110. Within the safe enclosure of the floral envel- 

 opes stand the essential organs the stamens and pis- 

 tils clearly distinguishable from the perianth by their 

 more slight and delicate forms, and from each other by 

 various marks. In the complete flower the ANDRCECEUM 

 next succeeds the corolla in the order of position, 

 being the third set, counting from the calyx. 



