374 PLEIOTAXY. 



Comus mas and G< sttecica sometimes show a triple 

 involucre.^ Irmish^ records an analogous case in 

 Anemone Hepatka, wherein the involucre was doubled. 

 Similar augmentation occurs in cultivated Anemone. 

 In addition to the plants already mentioned, Engelmann^ " 

 mentions as having produced bracts in unwonted 

 numbers, Lytlirum Salimna, Flantago major, Veronica 

 spicata, Echium vulgare, Melilotus arvensis, and Bubus 

 fruticosus. 



It must here be remarked that this great number of 

 the bracts occurs naturally in such plants as Godoya, 

 in which the bracts, or, as some consider them, the 

 segments of the calyx, are very numerous, and arranged 

 in several overlapping segments. 



In some of the cultivated double varieties of Nigella 

 the finely divided involucral bracts are repeated over 

 and over again, but on a diminished scale, to the exclu- 

 sion of all the other parts of the flower. 



Pleiotaxy or repetition of the calyx. The true calyx is 

 very seldom affected in this manner, unless such organs 

 as the epicalyx of mallows, Potentilla, &c., be considered 

 as really parts of the calyx. 



In Linaria vulgaris Keeper observed a calyx con- 

 sisting of a double series, each of five sepals, in con- 

 junction with other changes.^ It is also common in 

 double columbines, delphiniums, nigellas, &c. 



In the ' Revue Horticole,' 1867, p. 71, fig. 9, is de- 

 scribed and figured by M. B. Yerlot a curious variety 

 of vine grown for years in the Botanic Garden at 

 Grenoble, under the name of the double-flowered vine. 

 The place of the flower is occupied by a large number 

 of successive whorls of sepals disposed in regular 

 order, and without any trace of the other portions of 

 the flower. It is, in fact, more like a leaf-bud than a 



Weber. Verhandl. Nat. Hist. Vereins. Rhein. Pruss.,' 1860. 

 'Bot. Zeit.,'1848, p. 217. 



> 'DeAnthol.,'p. 17. 12. 



* ' Linna^,' vol. ii, 1827, p. 85. 



