CALYX. 61 



when not green, it is said to be colored. This organ is an expansion of the bark of 

 the flower-stalk, as appears from its color and texture. The calyx usually envelops 

 the corolla, previous to its expansion, and afterward remains below or around its 

 base. 



b. In the calyx are three parts, very distinct in calyces wliich are long and cylin- 

 dric : these are, 1st, the tube, which rises from the base ; 2d, the throat, above the 

 tube ; and 3d, the mouth, or the upper and expanded part ; the tube of the calyx 

 is cylindrk in the pink, and prismatic in the stramonium. 



0. The position of the calyx with respect to the ovary ofVers an important mark of 

 distinction between different genera, and also between different natural families of 

 plants. The calyx is said to be superior wdicn it is situated on the siunmit of the 

 ovary, as in the apple ; it is inferior when situated below the ovary, as in the pink. 

 In many plants the calyx is neither superior nor inferior, but is situated around 

 the ovary. When the calyx drops off before the flower fully expands, it is called 

 caducous ; the petals of the poppy are, at first, inclosed in a calyx of two sepals, 

 but these fall off before the flower is full blown. When the calyx withers, and 

 drops off wit.h the corolla, it is called deciduous ; when it remains until the fruit is 

 matured, it is called persistent. Upon a pea-pod the calyx may be seen as perfect 

 as it was in the blossom. The tube of the calyx is sometimes united to the pistil, 

 and enlarges so as to form a part of the fruit, as in the apple, pear, <fec., where the 

 dry sepals may be seen on the summit of the fruit. In the wintergreen (Gaulthe- 

 ria procumbens) the berries consist of the inflated, juicy sepals. 



68. Perianth (from the Greek, jpeT% around, aiitlios^ flower). 

 This is the only real cup or calyx ; — in the rose it is 'wr/i-form, 

 with leaf-like divisions at the top. In the pink, the perianth is 

 long and tubular, having the border dentate or toothed. The 

 hollyhock has a double perianth. ITie term perianth is used 

 when a flower has but one envelope, as in the tulip ; it is often 

 difficult to determine whether this envelope should be called a 

 corolla or calyx. Involucrum (from the Latin, in'volvo^ to 

 wrap up) ; this kind of calyx is usually found at the base of an 

 umbel, as in the carrot. It is composed of several bracts, some- 

 times very small, crowded into a whorl. The involucrum is 

 said to be itnwersal^ when it belongs equally to the whole of 

 an aggregate flower; and jxirtial^^ when it incloses one floret, 

 which with others constitutes a compound or aggregate flower. 

 The term involucrum is also applied to the membraneous cover- 

 ing in the fructification of ferns. Ament or catMn-\ (by some 

 classed as a mode of inflorescence) consists of many chaffy 

 scales, ranged along a thread-like stalk or receptacle ; each 

 scale protects one or more of the stamens or pistils, the whole 

 forming one aggregate flower. The ament is common to forest- 

 trees, as the oak and chestnut ; and is also found upon the wil- 

 low and poplar. In some trees the staminate flowers are inclo- 

 sed in an ament, and the pistillate in a perianth. The Spat/ia, 

 or sheath, first incloses the flower, and, when this expands, 

 bursts lengthwise and often appears at some distance below it. 

 This is, by some botanists, considered as a ])etaloid tract. It 



• See Fig. 135, a a. t See Fig 95. 



h. I'arts of the lalyx — c. Position with respect to the ovary. — Ji8. Perianth — Involucrum— Ament- 



i.itha. 



