Let me go back a few days though. One day last week, I was able to get out of work a bit earlier than normal. I decided since I actually had a bit of time before getting home, I would pick up some flowers for my wife, because she's awesome and sometimes I like to get her flowers to let her know she's awesome. They had lilies, which my wife is fond of, so that was the flower of choice.
Today, I remembered, or thought I remembered at least, that if you add food coloring to the water in a vase, then the coloring would eventually end up showing in the flower petals. After asking my wife's permission (they were her lilies after all) I got my older son to help me add some maroon food coloring and a bit of extra water to the vase. I also re-cut the stems, about 1 cm of the end of each, in the possibly mistaken belief that this would help speed up the uptake of the new water.
We also started a table to keep track of our observations, seen below. You can tell that I am a terrible speller without spell checker.
Figure teaching my son bad science habits like using pencil instead of pen
As you can see from our second observation, we actually started to see some change around the edges of the flower petals in the form of red "tick" marks. Since I now carry a camera around with me everywhere, just like almost everybody else in this country, I decided to take a picture:
Figure you know you're looking at sex organs, right?
It's hard to see it from the whole picture, so here is a zoom in near the tip of the flower petal on the bottom:
Figure my phone takes better pictures than I thought it could, this was simply a crop
One thing I was really surprised by was the first presence of the dye on the tips of the petals. I was expecting to see "rays" of red emanating from the center of the flower. But then, that is why you do the experiment! :)
Now I am running the program ChronoLapse and have set the lily up in front of my webcam to see if I can get a time lapse video out of it that shows something cool, hopefully the pigment either getting darker or spreading out more. If the video turns out well I'll probably post it. however, my web cam is hard to focus well, and has a resolution of 640 x 480, so cropping won't give me the zoom in effect like it does on my phone. However, if dramatic changes do occur, it should be a pretty cool video.
There is also always the possibility that Big Foot will break into our house to smell the color changing Lilies. Or the two-year old could become involved.
The best part of all of this? My son is super excited to make observations and see how it changes. Yay science!
UPDATE: The time lapse video didn't show much in the way of color spread. It did, however, show what happens during the sunrise which was pretty cool. The "ticks" on the petal edges are now darker, and we saw some red splotches on the outside of the closed flowers as well.
Figure I'm even less witty in the morning
I did this recently while teaching a lab on water movement in plants. We were using sunflower stems that had several leaves (no bloom). Cutting the stem allows an air bubble in the xylem that inhibits transpiration, but if you cut it again (about 1-1.5" from the base) *under water*, it should maintain the tension it depends on to pull the water up. Then we immediately transferred it to a dye (I think there was something special about this dye, though I forget what, it was probably hypotonic to the cells, I'd guess; I got the impression it was quite expensive and they've been reusing this same batch on this lab for years).
ReplyDeleteThen we had different lab groups remove it (and immediately remove all the leaves, to stop evaporation through the stomata) at different times and start cutting the stem to determine how far up the stem the dye made it. The problem is, (when it worked) it was making it most of the way up the ~40cm stem in just a minute or two – it goes *quick*.
The rate of water movement should mostly depend on the surface area available for evaporation, I believe, so basically the surface area of the leaves. I doubt the flower petals are doing much/any gas exchange, though, since they're not doing photosynthesis, so that may make a big difference, depending on whether they also have leaves on them.
I'll be curious to hear how the rest of your experiment plays out, though, I'm super envious that you have such an enthusiastic "lab tech" assisting you. =)
That's really cool. However, I don't think we can make a cut underwater and keep the stem submerged all the way back into the vase due to the current vase geometry. We may have to do an experiment similar to that in the future.
DeleteWe are seeing the red dye in the petals though, and to my eye it is getting darker red over time.
You don't have to keep it under water, just make the cut under water, and then transfer it quickly. The reason is that when you make a cut in the air, you're breaking the tension that's trying to pull all that water up, and the water in the upper xylem snaps up a bit, like a spring. Cut it under water, and it's replaced by more water when it does that. Then you can transfer it to the vase without having to worry, the water will stay put like water in a straw when you're covering the other end.
ReplyDeleteBut since you're seeing the dye anyway, it sounds like it worked well enough already without that precaution.