ii6 DAISY, INULA, TUSSILAGO. [chap. 



but differs in possessing scales between all, or at least" 

 the central, florets of the receptacle. 



The Common TizAsry {Bellis perennis) has ray florets 

 I — 2 mm. in length, united into a yellow disk 6 mm. 

 in diameter, and surrounded by a row of florets, each 

 terminating in a white " flag " 5 mm. in length. These 

 ray florets are exclusively female, and the pistil has 

 lost the terminal brush of hairs. The two branches are 

 long and clothed on their whole upper surfaces with 

 rows of stigmatic papillae. The pistil of the ray 

 flowers, on the contrary, has short branches, terminat- 

 ing in a tuft of hairs, and only provided with a small 

 number of stigmatic papillae. When fertilised, the 

 pistil retires again into the tube of the floret. 



In Inula dysenterica (the Fleabane) the disk florets 

 contain both stamens and pistil; the ray florets a 

 pistil only, which, however, agrees exactly with that of 

 the disk florets, even in the position of the terminal 

 hairs, which in the absence of pollen, must apparently 

 be useless. 



In Tussilago farfara the disk florets are male, the 

 ray florets female. In the disk florets the ovary is 

 rudimentary ; they contain honey at the base of the 

 tube, which has a length of 4 mm. The pistil 

 terminates in the usual tuft of hairs. The ray 

 florets, on the contrary, produce no pollen ; they open, 

 and as the stigmas are mature, before the anther 

 tubes of the disk flowers have opened, they are in fine 

 weather almost always fertilised by the pollen from 

 other flowers. 



In the Common Groundsel {Senepio vulgaris), 60 to 

 80 florets e^re united on one receptacle. The lower, 



