I am doing a science research project to determine the effect of CO2 on plant growth.

I need to find a plant that grows in the Woodlands (prairie plants would have worked as well, but I had to choose from between the two forums). This plant needs to start growing pretty fast after planting, and needs to be small enough to fit within a terrarium, but not too small. It needs to be TALL, meaning it grows straight up, as this would make it easier to measure its growth. It also needs to be manageable, easy to grow, and fairly cheap as I need a large number of them for my experiments.

Help would be highly appreciated. You don't need to post everything about the plant, if you just provide a name I could search it up for growing instructions and the like. That would save you some time.

Thank you once again.

How about something like plain ol' grass or wheat (if you purchase wheat straw at the hardware store it usually has viable seed in it)? Things that grow in woodlands aren't necessarily fast growing things (except for weeds!).

This time of year you can get spring bulbs (crocus, daffodils). Given the warmth/moisture of the terrarium they should sprout and grow.

Anyway, just some ideas.

My project necessitates the need for plants of the Woodland or the Prairie biome, because these are supposedly the most drastically affected by CO2. I will definitely look into your suggestions, though, and do some research. Prairie grasses should do the trick.

Thank you!

You can probably buy prairie grass seed already cold stratified from a reputable native plant nursery like "Prairie Nursery" or "Ion Exchange".