Re: Why does a carnation turn two seperate colors?

Water moves up the carnation stem in the xylem (little tubes of dead hollow 
cells stacked one on top of the other). In a nonwoody dicot stem, such as 
carnation, xylem occurs in vascular bundles that in cross section form a circle 
near the edge of the stem. Certain vascular bundles supply certain petals and 
other vascular bundles supply other petals. There is very little side to side 
movement from one vascular bundle to another otherwise the dyes would mix.

If you cut the stem base into four parts, you could get petals of four different 
colors.


References


Xylem Introduction

Any introductory college botany text such as Stern, K.R. 1991. Introductory 
Plant Biology. Dubuque, IA: Wm. C. Brown.