260 



THE I'LOWKU. 



that an outer circle is suppressed.* For since tlie calyx is fre- 

 quently delicate and petal-like (in botanical language petaloid or 

 colored), and the corolla sometimes greenish 

 or leaf-like, the only real difference between 

 the two is, that the calyx represents the 

 outer, and the corolla the inner series ; and 

 even this distinction becomes more or less 

 arbitrary when either, or both, of these or- 

 gans consist of more than one circle. The 

 apparent obliteration of the cal}'x in some 

 *'° cases is owing to the entire cohesion of the 



tube with the ovary, and the reduction of the free portion, or limb, 

 to an obscure ring or border, either slightly toothed or cntii'c, as in 

 Aralia (Fig. 410), Fedia (Fig. 882), Cornus, the fertile flowers of 

 Nyssa, &c. In Composite, the partially obliterated limb of the 

 calyx, when present at all, consists of scales, teeth, bristles, or a 

 ring of slender hairs (as in the Thistle), and receives the name of 

 pappus. 



481. The petals, however, are frequently absent; when the flower 

 is said to be apetalous, as in the Anemone (Fig. 411), Clematis, 

 Caltha, &c., in the Crowfoot family, 

 other genera of which are furnished 

 with both calyx and corolla ; and as 

 in some species of Buckthorn, while 

 others have manifest althougli small 

 petals. They are constantly wanting 

 in a large number of families of Ex- 

 ogenous plants, which on this account 

 form the division Apetalce. When 

 the calyx is present ^vhile the corolla 

 is wanting, the flower is said to be 



monocldamydeous, that is, with a perianth (417) or floral envelope of 

 only one kind ; as in the cases above mentioned. 



* In our Northern Zanthoxylum tlic monochlamydcous jDCriiintli whicli is 

 present may, however, bo justly held to be the corolUi, and not the cah-x, be- 

 cause the five stamens alternate with it, just as they do with the undoubted 

 petals of Z. Carolinianum : in this case, therefore, we may say that the calyx, 

 and not the corolla, is suppressed. See Genera Illustrata, Vol. 2, p. 148, tab. 1.56." 



riG. 410. Flower of Aralia, nuaicaulis, vertically divided ; the limb of tlie calyx obsolete. 

 FIG. 411. Flower of Anemone Pennsylvanica ; apetalous, the calyx petaloid. 



