THE FLORAL ENVELOPES. 129 



of a calyx, and gave it the general name of corolla when by its 

 color and the delicacy of its tissue it approximated to that 

 organ. But this distinction is utterly worthless, for the same 

 organ may vary in color without changing its nature. Thus, 

 in the Fuchsia or lady's ear drop, and in Salvia splendens, one 

 of the Mexican sages, the calyx is of the same bright- scarlet 

 color as the corolla ; and in the white water-lily and magnolia, 

 the sepals gradually approximate in color to the petals. Hence 

 it is now agreed amongst botanists when a flower has but one 

 envelope to its stamens and pistils, to consider it as a calyx, 

 whatever may be its color and form. 



The corolla, from " corolla" a garland, is that part of the 

 flower situated immediately within the calyx, between the calyx 

 and stamens. It is generally the most showy and beautifully 

 colored of all the floral organs, and is the part which is popularly 

 called the flower. Thus the red leaves of the rose, the yellow 

 leaves of the buttercup, constitute the corolla of these plants. 



The divisions of the corolla are called petals from {ji^taxov a 

 leaf.) If these petals are united by their margins so as to form 

 apparently one petal, as in the primrose and Campanula the 

 corolla is termed monopetalous ; if, 'on the contrary, the petals 

 do not cohere together, but grow separately and distinctly apart 

 as in the rose, the corolla is said to be polypetalous. When 

 the various divisions or petals of the corolla are alike and its 

 incisions uniform, the corolla is regular; if otherwise, it is 

 irregular. The lower part of a monopetalous corolla is called 

 the tube, the upper and expanded portion the limb, and the 

 part where the two are connected with each other the throat. 



The sepals of the polysepalous calyx are usually sessile 

 leaves, having nothing analogous to a leaf stalk at dieir base ; 

 but it is otherwise with the petals of the polypetalous corolla. 



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