FLOWER OP ALISMA, OR WATER PLANTAIN. 511 



Mono3cia), whilst the latter has the two sets of organs united in 

 each flower (and hence belongs to the Linnaean class Hexandria) : 

 the former also has more stamens than the latter. The Water 

 Plantain has oblong, heart-shaped, pointed leaves, marked 

 with about seven nearly parallel ribs or principal veins : and 

 these are united by cross-bars, so that a kind of network is 

 formed. The calyx consists of three distinct green sepals ; and 

 the corolla of three delicate pink or white petals. There are 

 six stamens in this species of Alisma, two placed opposite each 

 sepal ; so that there must evidently be some portion of the flower 

 deficient; since neither of these stamens corresponds with the 

 centre of the sepal, as it should truly do, but each with one of its 

 edges. Upon a more minute examination, a little glandular 

 body may be found at the base of each sepal, and between each 

 pair of stamens ; this is obviously a rudimentary stamen, and 

 thus the whole form an undeveloped whorl, perfectly opposite to 

 the sepals. But neither of the six stamens stand opposite the 

 petals, as one whorl should do if the flower were regular; so 

 that we must imagine the rudiments of another row to exist in a 

 state of still more complete want of development. In reality, 

 then, the flower of Alisma, although containing six stamens, or 

 two whorls only, must be regarded as constructed upon the plan 

 of twelve stamens in four whorls, of which the outer can only be 

 traced in a rudimentary state, the second being entirely deficient, 

 and the two inner ones only being apparent. This scheme of 

 suppression of parts may be expressed thus : 



The first line represents the position of the sepals ; the second 

 that of the petals alternating with them; the third that of the, 

 rudimentary stamens opposite the centre of the sepals ; the fourth 



