188 



ESSENTIAL ORGANS. STAMENS. 



391. 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 

 to stamens. Thus, in Nymphaea alba, or the White Water-lily (fig. 

 310, 2), c represents a sepal, which gradually passes into the petals, J9, 



310,1 



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 iuto petals, as in the Pasony, Camellia, Rose, 

 Anemone, and Tulip ; and in these instances, the changes from one 

 to the other may be traced in the same way as in the Water-lily. 



392. When there is only one whorl, the stamens are usually equal 

 in number to the sepals or petals, and are arranged opposite to the 

 former, and alternate with the latter. The flower is then isostemonous 

 (fro?, equal, and arviftuv, a stamen). When the stamens are not equal 

 in number to the sepals or petals, the flower is anisostemonous (oiviaos, 

 unequal). When there is more than one whorl of stamens, then the 

 parts of each successive whorl are alternate with those preceding it. 

 The stamina! row is more liable to multiplication of parts than the 

 outer whorls. If the stamens are double the sepals or petals as regards 

 number, the flower is diplostemonous (liif^oog, double) ; if more than 

 double, polystemonous (woXvj, many). In general, when the stamens 



Fig. 310, 1, Flower of Nymphsea alba, or White Water-lily, cccc, The four foliola of the 

 calyx or sepals, p p p p, Petals, e, Stamens, s, Pistil. 



Fig. 310, <?. 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 fonns, 4, 3, 2, and 1, which gradually resemble 

 the petals. 



