152 MANUAL OF BOTANY 



terms used in defining these modifications are the same as 

 those applied to the blades of leaves. 



Sepals are almost without exception destitute of a stalk, or, 

 in other words, they are sessile upon the thalamus. They are 

 also generally entire at their margins, although exceptions to 

 this latter character occasionally occur : thus, in the Pa;ony and 

 Rose {figs. 285, <•/, and 302, cf), the sepals are incised; in 

 many species of Dock they are toothed ; in Chammlaucium 

 plumosum each sepal is divided into five deep lobes or parti- 

 tions ; and in Passiflora foetida the sepals are first pinnatisected, 

 and then each segment pinnatifid. 



The sepals may be either distinct from each other, as in the 

 Poppy, Buttercup, "Wallflower, and Strawberry (fig. 267) ; or 

 more or less united into one body, as in the Pimpernel (fig. 

 287), Campion, and Henbane (fig. 288). In the former case the 

 calyx is usually termed polysepalous, or dialyaepalous ; in the 

 latter it is commonly called gamosepalous. 



1. PoLYSEPALOus OE DiALYSEPALOus Calyx. — A polysepa- 

 lous calyx may consist of two or more parts, the number being 

 indicated by a prefix of Greek numerals ; as disepalous for a 

 calyx composed of two distinct sepals, trisepalous for one with 

 three, and so on. 



A polysepalous calyx is called regular if it consists of sepals 

 of equal size and similar form, and is arranged in a sym- 

 metrical manner, as in the species of Itanunculus (fig. 227) ; 

 and it is said to be irregular when the sepals vary in these 

 particulars, as in the Monkshood (fig. 286). 



2. Gamosepalous Calyx. — When the sepals are united so 

 as to form a gamosepalous calyx, various terms are used to 

 indicate the different degrees of union. Thus, the union may 

 only take place near the base, as in the Pimpernel (fig. 287), 

 when the calyx is said to be partite \ or it may take place to 

 about the middle, as in the Centaury, when it is cleft or fissured ; 

 or the sepals may be united almost to the top, as in the 

 Campion, when it is toothed ; or the union may be quite complete, 

 when it is entire. The number of partitions, fissures, or teeth is 

 indicated by the same prefixes as those previously referred to 

 as used in describing the divisions in the lamina of a leaf, 

 and in the majority of cases it corresponds to that of the 

 component sepals of which the calj'X is formed ; although 

 exceptions to this rule sometimes occur, as for instance in those 

 cases where the divisions are themselves divided into others. 

 A little care in the examination will, however, generally enable 



