FLORAL ENVELOPES. CALYX. 



175 



ripens, it is shown to consist of hairs rolled inwards, which expand so 

 as to waft the fruit. 



366. The calyx sometimes falls off before the flower expands, as in 

 Poppies, and is caducous ; or along with the corolla, as in Ranunculus, 

 and is deciduous ; or it remains after flowering, as in Labiatae, Scrophu- 

 lariaceas, and Boraginacese ; or its base only is persistent, as in Datura 

 Stramonium. In Eschscholtzia and Eucalyptus, the parts of the calyx 

 remain united at the upper part, and become disarticulated at the base 

 or middle, so as to come off in the form of a lid or funnel. Such a 

 calyx is operculate (operculum, a lid), or calyptrate (x.*i/7rToe., a cover- 

 ing). The existence or non-existence of an articulation determines 

 the deciduous or persistent nature of the calyx. In the case of Esch- 

 scholtzia, the axis seems to be prolonged so as to form a sort of tube, 

 from which the calyx separates. In Eucalyp- 

 tus, the calyx consists of leaves, the laminae or 



petioles of which are articulated like those of 

 the Orange, and the separation between the 

 parts occurs at this articulation. 



367. The tube of the calyx is sometimes 

 united to the pistil, and enlarges subsequently, 

 so as to form a part of the fruit, as in the Apple, 

 Pear, Pomegranate, Gooseberry, &c. In these 

 fruits the limb of the calyx is seen at the apex. 

 Sometimes a persistent calyx increases much 

 after flowering, without being incorporated with 

 the fruit, becoming accrescent (accresco, to in- 

 crease), as in various species of Physalis (fig. 280); 



Figs. 277279.- 

 hairs or pappus. 



column above it, in ngs. 440, tiy, mu nmu, t, irons 

 i Involucre or gamosepalous bracts cut vertically. 



Fig. 277. Calyx of Catananche coerulea. 



Fig. 278. Calyx of Scabiosa atro-purpurea. 



Fig. 279. Calyx of Pterocephalus palffiStlmu, 



Fig. 280. Accrescent calyx, c, connected with the fruit of Physalis alkekengi. 



