64: COROLLA. 



cately shaded, and blended ; in others, they meet abruptly, without any interme- 

 diate thit. The color of the corolla, in the same species, often varies without any 

 assignable cause. This fact is 8ii;rikingly illustrated in the four o clock (Mirabilis) ; 

 the flowers of whicli are sometimes of pale yellow, sometimes bright crimson, and 

 often richly variegated. The florist watclies these changes, and, as far as possible, 

 avails himself of them in the production of new beauties in the vegetable kingdom. 

 The corolla before blos>;oming is folded in the calyx, as the leaves are within the 

 scales (jf the leaf-bud. In most cases, the calyx and corolla are distinctly marked. 

 The color usually constitutes a striking mark of difterence ; the calyx being ordi- 

 narily green, and the corolla of a more lively hue. Rut tlie color is not always a 

 criterion, for in some cases the calyx is beautifully colored. In the Fuschia 

 {Lady's ear-drop), the calyx is of a bright scarlet ; we might at first think it to be 

 the corolla ; but on removing tlie scarlet coat we see, wrapped around the eight 

 stamens, a purple covering ; on taking off each piece carefully, we find four petals, 

 as distinct as the petals of a rose. 



Yl. Tlie parts of tlie corolla or petals, according to normal 

 arrangement, alternate with the sepals, and either equal them, 

 or are some multiple of their number. But this symmetrical 

 arrangement of nature is often broken up, by j^eculiar circum- 

 stances attending the growth, as in choeisis or dedoiiblement^ 

 which terms signify unlinhig^ meaning that the organ in question 

 unlines or separates into two or more layers, each having the 

 same structure, and thus increasing the normal nionher ol 

 organs. When the corolla falls off soon after flowering, as in 

 the poppy, it is said to be caducous / when it fades and with- 

 ers upon the stalk, as in the blue-bell, it is then said to be 

 marescent, A flower without petals is said to be a^etalous. 

 Petals are said to be definite when their number is not more 

 than twenty ; indefinite^ when they exceed that number. The 

 parts into which a corolla naturally falls, may be considered as 

 so many petals. Tlie name jpolypetcdous is given to corollas 

 having separate petals, while moiiojyetalous is applied to those 

 which appear to have but one petal ; but, as it is now admitted 

 that all corollas are formed of several united petals, the term 

 gamojMalotis (from gamos^ union), or united petals, is often 

 used ; yet, as the term monopetalous has been incorporated into 

 the science of botany, it continues in use. The union of jjetals 

 generally takes place at the base, and extends more or less 

 toward the apex. Ifonojyetalous corollas (or when the petals 

 unite so as to form but one piece) consist of the tuhe^ throaty 

 and linib. The tid>e is the lower part : the throat the entrance 

 into the tube ; it is either open, or closed by scales or hairs. 

 The lamina or limb is the upper border of the corolla. In Poly- 

 jyetalous corollas^ each petal consists of two parts, the lamina 

 and claw. Petals, properly so called, belong to Exogenous 

 plants, for in the Endogenous, the flower consists of a perianth, 

 which is considered as a calycine envelope. The venation of 

 petals resembles that of the leaves of Exogenous plants ; the 



Its situation before expanding — How distingnished froK tiie cdvx ?— 7J Noraia.1 arrangement of the 

 l>"!;il?— Duration— Parts of the corolla — Forms of monopetalous corolla. 



