328 PAPPUS SUPERIOR AND INFERIOR CALYX. [BOOK i. 



latter, two of the sepals separate, the cohesion between the 

 remainder continuing complete. 



The calyx of Composites is so very different in appearance 

 from the calyx of other plants, that it is known by the par- 

 ticular name of. pappus. It usually consists of hair-like pro- 

 cesses proceeding from the apex of the ovary, in which case it 

 is said to be pilose : if those hairs are themselves divided, it 

 is plumose ; if they are very unusually stiff, it is setose, in 

 which case the setae are often reduced in number to two, or 

 even one ; if the divisions of the pappus are broad and mem- 

 branous, it is said to be paleaceous : finally, it is sometimes 

 reduced to a mere rim : in which case it is said either to be 

 marginate, or to be none to have no existence. A calyx 

 appears to be brought into this state by having no room to 

 develope, in consequence of the pressure of the surrounding 

 flowers. In such cases as this, where the calyx is altogether 

 obsolete, the definition of that organ, as the most external of 

 the floral envelopes, appears to be destroyed : but there can 

 be no doubt that it is present in the form of a membrane 

 adhering to the side of the ovary, although it is not visible 

 to our eyes. The same may be said of such plants as those 

 Acanthads (Vegetable Kingdom, p. 678), in which, although 

 the calyx is reduced to a mere ring, yet it does exist in the 

 shape of that ring. 



The Calyx being composed of leaves analogous to those of 

 the stem, but reduced in size and altered in appearance, it 

 will follow that it is subject to the same laws of development 

 as stem-leaves ; and, as the latter, in all cases, originate 

 immediately from the axis, below those that succeed them in 

 the order of development, so the calyx must always have an 

 origin beneath those other organs which succeed it in the 

 form of corolla, stamen, and pistil or ovary. Hence has 

 arisen the axiom in botany, that whatever the apparent sta- 

 tion of the calyx may be, it always derives its origin from 

 below the ovary : nevertheless, it is often said to be superior. 



If it is distinct from the ovary, as in Silene, it is said to 

 be inferior or free (calyx inferus, or liberus) ; and the ovary 

 is then called superior (ovarium superum, or liberum] (Plate V. 

 fig. 3.) ; but if it is firmly attached to the sides of the ovary, 



