BOTANY. 05 



rest ; carinary, Avhcre the carina performs a similar ofBce. Calyx and corolla 

 sometimes exhibit different aestivation. 



The Calyx is the external envelope of the flower, and consists of Avhorled 

 leaves, called sepals. These may either be separate, forming a poli/scpaloiis 

 calyx, or united, to constitute a gamosepaloii.s, or moiwsepalous calyx. The 

 sepals are usually green, sometimes colored, rarely stalked ; in shape, they 

 are generally oval or oblong. As to direction, they are erect, reßcxed, 

 patulous, or divergent (spreading outwards), and conmvent or arched 

 inwards. A trisepalous calyx has three divisions : a pentasepalous, five, 

 <fcc. 



In a gamosepalous calyx the degrees of adhesion between the elementary 

 parts may vary from very slight to complete. The divisions may be simple 

 teeth, or they may extend as fissures towards the base. A trifid calyx is 

 one in which three parts are united by about the lower half of the margins ; 

 a tripartite is one where only the lower part of the edges is so united. 

 The calyx may also be quadrifid, quadripartite, quinquifid, (j^uinquepartite, 

 &c. The adhesion is sometimes irregular, some parts uniting to a greater 

 extent than others ; in this manner may be formed a two-lipped or labiate 

 calyx, which becomes ringent when tlic upper lip is arched. The part 

 formed by the union of the sepals is called the tube ; the free upper portion, 

 the limb. 



Occasionally a flower is provided with a douhle calyx, the outer of which 

 is called epicalyx, or calicle. The calyx, again, may degenerate, so as to 

 become dry, scalj^^, and glumaceous ; or it may he obsolete or marginate, 

 existing only as a mere rim. In some families, as Dipsacci^, the tube of the 

 calyx adheres to the pistil, and the limb is developed in the form of hairs, 

 called pappus. The pappus is either simple {pilose) or feathery (plur/iose). 

 When the calyx falls off before the flower expands, it is caducous ; or if the 

 corolla accomj)any it, deciduous. Sometimes the tube of the cal^'x is 

 united to the pistil, and enlarges with it to form part of the fruit, as in the 

 apple. A persistent calyx, which increases after flowering, is called 

 accrescent ; it may, again, remain withered or marcescent, or become inflated 

 or vesicular. 



Corolla. The corolla is that more or less colored inner floral envelope 

 between the calyx and the stamens. The free subdivisions, which are gen- 

 erally disposed in one or more wdiorls, are called petals. A petal frequently 

 exhibits two parts ; a claw or unguis, a narrowed part b}'^ which attachment 

 is made to i\)§ axis, and a broad expanded portion above this, called the 

 lamina, or limb. When there is no claw the petal is sessile. 



Petals, in their modifications, exhibit a considerable resemblance to ordinary 

 leaves, in having the margin either entire or indented. A single petal may 

 be bipartite or bifid, (fcc. When a petal is folded like a boat, it is cymbiforni 

 or navicular: cochleariform, when resembling the howl of a spoon. When a 

 petal is prolonged backwards, in the form of a spur, it is calcarate. When 

 the spur is very short and rounded the petal is gibbous. 



When hut a single petal is present, the rest being abortive, the flower is 

 tinipetalous ; two, three, four, five, &c., petals constitute a di-, tri-, tetra-, or 



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