|MadSci Network: Botany|
This sounds like a very interesting project. You might discover some better or cheaper flower dyes than food coloring. One student noticed that a yellow food coloring moved faster than other colorings but I did not test this myself. I'm sure you could find dyes that move at different rates or not at all. I can't guarantee they will all work, but here's some readily available things to try: 1. India ink, which is available at an office supply or art store. 2. A hot water extract of anthocyanins from red cabbage or red onions. 3. Red beet juice, which contains betalains. 4. Chlorophyll extract in rubbing alcohol or denatured alcohol. 5. Yellow dye obtained from dry onion skins. It is often used to dye Easter eggs. 6. Iodine solution from the drugstore diluted by twenty in water, which is used to test for starch. 7. Saffron, a water-soluble yellow spice available at the supermarket. Saffron is the stigmas of the saffron crocus. 8. Tea. 9. Bluing, a laundry bleaching compound available at a supermarket. Mrs. Stewart's Bluing is a solution of fine blue iron particles suspended in water. 10. Kool Aid without the sugar. It comes in many colors. If you have a local florist who dyes their own flowers, they may be able to sell you small amounts of the dyes they use. Scientific supply companies sell a wide variety of stains that you might try such toluidine blue, congo red and malachite green. Stains are classified as acid or basic. You might see if acid or basic stains travel at different speeds. There are many dyes that can be extracted from plant materials you could test. References Re: why is yellow food colouring sucked up by flowers more quickly? Stains and Dyes List Making Natural Dyes From Plants
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