M. WICHURA ON THE WINDING OP LEAVES. 303 



§ 114. 



SilenecB. — Dianthus diutinus, Kit. ; D. atrorubens. All. ; D. tri- 

 fasciculatus, W. et K. (fig. 9) : stem-leaves left. Dianthus, Gyp- 

 sopldla, Saponaria, Vaccaria, and generally, apparently, in the 

 Silenece with only two styles: petals to the left in the bud. 

 The peculiar twisting of the petals in a direction contrary to 

 that of the spiral of the sepals peculiar to the Silenece with three 

 or five styles, and already spoken of above, does not present itself 

 distinctly in all the species. Thus, for example, I observed in 

 Lychnis chalcedonica, L., Silene Armeria^ L., and many other 

 Silenece, that the left-wound buds predominate; while, if the 

 petals of every bud were wound contrary to the direction of the 

 spiral of the sepals, right- and left- wound flower-buds ought to 

 exist in equal numbers, since the leaf- and consequently the 

 sepal-spirals of each pair of opposite branches of the inflorescence 

 of this family are wound in contrary directions. Such examples 

 of plants with prevailing but not exclusively left- wound flower- 

 buds form the transition from the Silenece with petals wound 

 contrary to the direction of the sepal-spiral, — in which, there- 

 fore, on account of the antidromy of opposite flower-branches, 

 right- and left- wound flower-buds alternate regularly, — to the 

 two-styled Silenece with only left-wound buds. Agrostemma 

 Githayo is a plant in which the sepal-spiral may be particularly 

 easily made out from the imbrication of the teeth of the calyx, 

 and I recommend it for investigation of this point. It shows 

 the law prevailing in the three- or many- styled Silenece with 

 almost unalterable regularity. Dianthus deltoides, L. ; Lychnis 

 coronaria, Lam. ; L, chalcedonica, L. ; L, Flos-cuculi, L. ; Silene 

 repens, Patrin., &c. ; style right. 



§115. 



Frankeniacece, — Frankenia campestris, Schauer. ; F.pulveru- 

 lenta, L. : tube of calyx right. 



§ 116. 



Loasece, — Loasa lateritia. Gill, et Hook.: capsules mostly 

 wound to the right, more rarely to the left. Blumenbachia in- 

 signis, iSchrad. : capsules right. 



