ORGANS OF REPRODUCTION. 



227 



order Composite and the allied orders Dipsacese and Valeria- 

 nacere, the hmb of the calyx is only developed in the form of 

 a circle, or tuft of bristles or hairs, to Avhich the name of pappus 

 is given, and the calyx under such circumstances is said to be 

 pappose. The pappus is described as feathery or plumose, and 

 simple or pilose; thus it \s> feathery, as in the Valerian {fig. 452), 



Fig. 452. 



Fig. 453. 



- W^^^lUJi 



Fig, 452. Fruit of Valerian surmounted by a feathery sessile pappus 



Fig. 453. Fruit of Scabious surmounted by a stalked pilose pappus. 



and Salsafy, when each of its divisions is covered on the sides 

 by little hair-like projections aiTanged Hke the barbs of a 

 feather ; it is pilose, when the divisions have no visible pro- 

 jections from their sides, as in the Dandelion and Scabious 

 {fig. 453). The pappus is also described as sessile when it arises 

 immediately from the tube of the adherent calyx, and thus ap- 

 parently from the top of the ovary, as in the Valerian {fig. 452) ; 

 and stalked or stipitate, if it is raised above the ovary on a 

 stalk, as in the Dandelion and Scabious {fig. 453). 



The calyx, whether monosepalous or polysepalous, is subject 

 to various irregularities besides those already alluded to, arising 

 from the expansion of one or more of its sepals into append- 

 ages of various kinds ; some of the more important of these 

 may be briefly alluded to. Thus in the Monkshood {Aconitum) 

 {fig. 442), the superior sepal is prolonged upwards into a sort 

 of hood or helmet-shaped process, in which case it is said to be 

 hooded, helmet-shaped, or galeate. In the Wallflower {Cheiran- 

 thus) {fig. 421), and other plants of the Cruciferce, the two 

 lateral sepals are expanded on one side at the base into httle 

 sacs, when they are termed gibbous or saccate. The latter term 

 is only apphed by some botanists when the sac-Hke form of the 

 Q2 



