ROUND-LEAVED MALLOW. 27 



acquainted with all the parts that any leaf has, viz., blade, 

 petiole, and stipules. 



34. Coming to the flower, observe first that the parts 

 of the calyx are not entirely separate, as in the flowers 

 you have already examined. For about half their length 

 they are united together so as to form a cup. The upper 

 half of each sepal, however, is perfectly distinct, and 

 forms a tooth of the calyx ; and the fact that there are 

 five of these teeth shows us unmistakably that the calyx 

 is made up of five sepals. We therefore speak of it as a 

 gamosepalous calyx, to indicate that the parts of it are 

 coherent. 



As the calyx does not fall away when the other parts 

 of the flower disappear, it is said to be persistent. Fig. 

 31, a, shows a persist-eut calyx. 



35. At the base of the calyx there are three minute 

 leaf-like teeth, looking almost like an outer calyx. A 

 circle of bracts of this kind is called an involucre. The 

 three bracts under the flewer of the Hepatica also consti- 

 tute an involucre. As the bracts in the Mallow grow on 

 the calyx, some botanists speak of them as an epicalyx. 



The corolla consists of five petals, separate from each 

 other, but united with the stamens at their base. 



36. The stamens are numerous, and as their filaments 

 are united to form a tube, they are said to be monadelphous. 

 This tube springs from the receptacle, and the stamens are 

 therefore hypogynous. Fig. 32 will help you to an under- 

 standing of the relation between the petals and stamens. 



Having removed the petals, split the tube of the stamens 

 with the point of your needle. A little care will then 

 enable you to remove the stamens without injuring the 



