I50 CLEOME PUNGENS. PRICKLY CLEOME, OR SPIDERFLOWER. 



other more minute but essential peculiarities, will show at once 

 the difference between our plant and the Crucifera. 



But there are still other plants belonging to the same natural 

 order with Cleome which have the petals ranged with more 

 regularity around the axis, in which the ovary is borne on a 

 much shorter pedicel, and which, therefore, point to a much 

 closer relationship to cruciferous plants than that suggested by 

 the plant to which this chapter is devoted. Nor is this sugges- 

 tion deceptive ; for the order Capparidacece, to which our species 

 belongs, is closely allied to Crucifercz, and quite as much so, if 

 not still more closely, to Resedacece, or mignonettes. With the 

 violets it also has some affinity, and it has therefore been classed 

 near them. The Crucifercz comprise a very large number of 

 genera and species, while the Capparidacece and the Rcscdaccce 

 have each but a very few ; and it will be well to look for " miss- 

 ing links " in their development, as it is not improbable that 

 both of them had cruciferous parentage. 



A fair key to the structure of our species is supplied by the 

 numerous bracts among the flowers. In the true Cmciferce 

 there is nothing but a naked flower-stalk bearing pedicels and 

 flowers, and the bracts are entirely wanting. We see, also, that 

 the foliaceous system of our plant is very well developed, and 

 this, in plants not absolutely acaulescent, generally implies a 

 corresponding activity in the axis or stem. In other genera of 

 Capparids, where there are no bracts, there is scarcely any pedi- 

 cel to the flower, or to the ovary, and the resemblance to true 

 Crucifcrcc is every way closer. In this species, however, the ten- 

 dency to produce stems is so strong that even the petals are 

 stalked, while the stamens have long, drawn-out filaments, and 

 the same force has projected the ovary far beyond the point 

 usual in flowers. 



We also see the operation of rhythmical growth, or of the 

 law of acceleration and retardation, as it is sometimes called, in 

 producing certain other results. The pedicel is really a branch, 

 which lias started to erow from the axial bud at the base of the 



