ITS IRREGULARITY. 



203 



470. In some few plants the stamens continue this adnation a little 

 further, and cohere with the style, either with its bate only, as in 

 some species of Asarum,orwithits 



whole length, as in Cypripedium 

 (Fig. 468) and the whole Orchis 

 family. Then the flower is said 

 to be gynandrous ; — from two 

 Greek words equivalent in mean- 

 ing to stamens and pistil com- 

 bined (519). 



471. Irregularity. The flower 



is irregular when the parts of its 

 different circles, or of one or 



more of them, are not all alike in number, 

 shape, or size. Irregularity may be the re- 

 sult, therefore, either of the abortion or dis- 

 appearance of some parts, or of their tin- 

 equal development or unequal ration. The 

 latter case may be first considered. 



472. The Pea tribe affords a familiar 

 illustration of irregidar flowers arising from 

 the unequal size and dissimilar 

 form of the floral envelopes ; 

 especially of the corolla, which, 

 from a fancied resemblance to a 

 butterfly in the flower of the 

 Pea, Locust (Fig. 392), &c, has 

 been called papilionaceous. The 

 petals of such a corolla are dis- 

 tinguished by separate names ; 

 the upper one, which is usually 

 most conspicuous, being termed 

 the vexilhtni, standard, or banner 

 (Fig. 392', a); the two lateral 

 (b) are called wings (alee), and 

 the two lower (c), which are 

 usually somewhat united along their anterior edges, and together 



FIG 391. Flower of Cranberry divided lengthwise, showing the petals and stamens epi- 

 gynous 



FIG. 302 Front view of a flower of the common Locust-tree (Uobiuia r-seudacacia). 



FIG 892'. Corolla of the same, the petals displayed. 



