STRUCTURE OF FLOWERS. 53 



The petals are almost always articulated with the 

 torus, and consequently Deciduous : frequently they 

 fall off very early, that is to say, before fecundation ; they 

 are then said to be Caducous : sometimes they are con- 

 tinuous or adherent, and then they are termed Persist- 

 ent — for example, in Campanula. 



When they are completely distinct from each other 

 down to the base, the corolla is said to be Polypeta- 

 lous, or, if it is wished to express the number of petals, 

 Di-, Tri-, Tetra-petalous. When they are more or 

 less united together, it is most frequently said, but in an 

 improper manner, that the corolla is Monopetalous, a 

 term for which I substitute that of Gamopetalous, 

 which signifies that the petals are united. This union 

 is seen to be the case, by the distribution of the vessels 

 in the greatest number of cases ; it is perceived 

 also more clearly in some plants, such as JRhodora 

 Canadensis, Campanula medium, or Phlox amccna, 

 (PL 18, figs. 8, 9, 10, 11) in which we frequently 

 find every degree of union which can possibly be met 

 with, whether in the flowers of the same individual, or 

 in the petals of the same flower. It happens in the 

 Compositor, that the five petals united into a tube, pre- 

 sent in certain flowers a lateral fissure, so deep that the 

 corolla, instead of appearing tubular, becomes strap- 

 shaped. This phenomenon is constant in the Chicoraceas, 

 where some ingenious philosophers attribute it to the 

 presence of glands which unite the lobes together at the 

 apex : in the other Compositae it only takes place in the 

 marginal flowers of the capitula, but here also we recog- 

 nise the original nature of ligulate flowers, in their 

 sometimes happening to retain their tubular form. 

 Thus, I have observed in gardens an accidental monstro- 

 sity of Tagetes erecta, where the semi-florets were 

 changed into tubular ones, larger than those of the disc. 



