THE FLOWER. 
81 
rolla persist, not only with reference to each other but 
in different plants. The parts are said to be caducous 
when they drop from the flower as soon as it opens, as 
the calyx of the poppy; when they remain for a day 
or so, they are said to be ephemeral or fugacious, as in 
the petals of the poppy ; in the rose and apple the 
petals fall away soon after the pollen reaches the stig- 
ma and they are said to be deciduous ; in some flowers 
the petals wither but persist until the maturing of the 
fruit, as in the Droseracese, and are known as marces- 
cent; the calyx may remain unaffected until the matur- 
ing of the fruit, as in the Labiatse, when it is said to 
be persistent; in the apple the calyx grows and becomes 
fleshy with the development of the ovary, when it is 
said to be accrescent. 
2. THE STAMENS. 
When a flower has hut one stamen it is termed mon- 
androus; and when there are two, three or many sta- 
mens, it is said to be diandrous, triandrous or poly- 
androus. The aggregate of stamens in a flower is 
called the androecium. In the Labiatse there are four 
stamens arranged in a longer and shorter pair and the 
androecium is said to be didynamous; in the Crucifersethe 
flowers possess six stamens, four of which are longer 
than the other two, and the androecium is described 
as tetradynamous ; in some plants, as in the Lobeliacese, 
Papilionacese, etc., the filaments of the stamens cohere, 
forming groups which are termed monadelphous, dia- 
delphous, etc. ; in the flowers of the potato the anthers 
lie close together but are not united, forming apparently 
a closed ring around the pistil, when they are said to 
be connivent; in the tubular flowers of the Compositse 
the anthers are united, forming a closed ring, and the 
stamens are spoken of as syngenesious ; in the flowers 
