214 



ESSENTIAL OEGANS — ^STAMENS. 



to be afterwards particularly noticed. For instance, the term tha- 

 lamifloral is applied to plants having a 

 polypetalous coroUa and all the whorls in- 

 serted immediately into the torus or thala- 

 mus ; calycifloral to those where the petals 

 are separate or united, and the stamens are 

 inserted directly on the calyx; coroUifloral 

 to those in which the united petals are 

 placed under the ovary, and the stamens are 

 either borne by them, or are inserted inde- 

 pendently into the torus. 



The stamens vary in number, from one to many hundred. Like 

 the other parts of the flower, they are modified leaves, resembling 

 them in their structure, development, and arrangement. They consist 

 of cellular and vascular tissue. They appear at first in the form of 

 cellular projections, and are arranged in a more or less spiral form. 

 In their general aspect they have a greater resemblance to petals than 

 to the leaves, and there is often seen a gradual transition from petals 



Fig. 340. 



Fig. 341. Fig. 342. 



to stamens. Thus, in Nymphsea alba, the White Water-lily (figs. 341, 

 342), c represents a sepal, which gradually passes into the petals, p, 

 and these in their turn become modified so as to form the stamens, e, 

 which are more or less perfect as we proceed from without inwards, 

 or from 1 to 5. When flowers become double by cultivation, the 

 stamens are converted into petals, as in the Pseony, Camellia, Rose, 



Fig. 340. Section of the flower of Aialia spinosa. Letters as in last figure. The petals 

 and stamens are epigynous, attached to the torus, d, which covers the summit of the 

 ovary. The ovary is adherent to the torus, and has been laid open to show its loculaments 

 and pendulous ovules. Fig. 341. Flower of Nymphsea alba, White Water-lily, cccc. 



The tour foliola of the calyx or sepals, p p p p, Petals, c. Stamens, s. Pistil. Fig. 342. 

 Parts of the flower separated to show the transition from the green sepals of the calyx, c, 

 and the white petals of the corolla, p, to the stamens, e. The latter present changes 

 from their perfect state, 5, through intermediate foiins, 4, 3, 2, and 1, which gradually re- 

 semble the petals. 



