FLOEAL ENVELOPES — CALYX. 



199 



In Compositse, Dipsacacese, and Valerianacese, the calyx is at- 

 tached to the pistil, and its limb is developed in the form of hairs, 

 called pappus. This pappus is either simple {pilose) (fig. 302), or 

 feathery {plumose) (fig. 303). In cases where, to the naked eye, 

 the hairs appear to be simple, the examination by a lens sometimes 

 exhibits distinct tooth-like projections often irregularly scattered. In 

 figs. 301, 302, 303, there are examples of calyces, c, which are 

 attached to the pistil, while their limbs, I, show the transition from 

 the narrowed thread-like form in Catananche cserulea (fig. 301) to 

 the pilose in Scabiosa atro-purpurea (fig. 302), and thence to the 

 plumose in Pterocephalus palsestinus (fig. 303). In Valeriana the 

 superior calyx is at first an obsolete rim, but as the fruit ripens, 

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

 waft the fruit. 



Fig. 301. 



Kg. 302. 



Fig. 303. 



The calyx sometimes falls oflf 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 Labiatse, Scrophu- 

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

 Stramonium. In Bschscholtzia and Eucalyptus the sepals remain 

 united at the upper part, and become disarticulated at the ba^e 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.aXh'XT^a, 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- 

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

 from which the calyx separates. In Eucalyptus the calyx consists of 

 leaves, the laminae or petioles of which are articulated like those of 



Figs. 301-303. Examples of calyces, the limbs of which, I, gradually pass into the state 

 of hairs or pappus, c t, Calyx, united to the ovary, and forming a narrow column ahove 

 it : in figs. 302, 303, the calyx ends in numerous simple .or feathery hairs, I. i. Involucre 

 or gamosepalous bracts cut vertically. Fig. 301. Calyx of Catananche cserulea. Fig. 

 302. Calyx of Scabiosa atro-purpurea. Fig. 303. Calyx of Pterocephalus palsestinus. 



