I would say a Syngonium (arrowhead plant.) When I had one it always seemed to lean one way or another no matter what I did!

Jen

I agree with Jen. I turn my arrowhead plant every day because it always lean's toward the window. You can notice the change daily.

Wow, great. I'm not sure what it is, but I'll do a search.

Coleus might work, too. Toni

I'll add pothos to the list. I have several in hanging pots and a large one in a container by a living room window. I have turn them often because they are reaching for the light. Good luck wiht the demenstration.
Ivan

almost any plant that has a wide leaf on a long petiole will show the phototropic effect most dramatically, try to find a plant that likes very bright conditions so it will stretch near a window

I dunno. I tried really hard to think of something that would show an effect as quickly and dramatically as a Syngonium, and I drew a blank. My runners-up were:

Crassula portulacea (jade plant)
Echeveria spp.
Synadenium grantii (African milk bush)
Tradescantia pallida (purple heart)
Tradescantia zebrina (wandering Jew)

Of those, the Echeveria I have seems to be the most dramatically phototropic.

Schefflera

LOL, poor Socks has a lot of research to do..Socks, you'll need a bright window to accomplish this project..How much time does this project have? You can always use a variety of plants just to add to the excitement..Lucky kids..Toni

It'll be an open ended project. I provide the 2nd grade teachers with the plants (6 classes), and they'll set them up in the classroom, and we can observe for however long it takes.

After I searched and saw the Arrowhead plant, I know what that is but never knew the name. Have seen it many times in nurseries, etc. I'll probably get one of those to experiment with before fall. I like the schefflera idea too as I have one in the yard that is leaning. Echeveria is good, Mr. Sub, but I think they are slow growers.

When I told my co-worker that I had asked my question on the GardenWeb forum, she was so impressed! She said, "You mean you are talking to strangers?!" Yep! LOL

Thank you, everyone.

2nd graders..good thing you're not going w/the Coleus..the leaves can be harmful if eaten.
Arrowhead/Syngonium is safe as far as I know...I can do a check if you'd like, or maybe someone here knows..
Socks, does this mean you'll be buying 6 plants?
Talking to strangers..lol..well, I guess we are at that..but friendly strangers..Toni

Unfortunately the arrowhead, being an aroid is more potent than the coleus. Some coleus are edible though, www.richters.com has some. Another thing would be scented geraniums, the kids could at to their hear's content an have no problems, you can even bake and make teas with them. just make sure the kids know that the plants are not food, you should be ok. second grade is old enough to know better. my daughter knew at age 2 she wasn't supposed to touch some plants and which ones.

I'm glad you mentioned the toxicity, Hopeful. I checked it out on UC Davis' website, and Arrowhead does have some toxicity, as does schefflera but not so bad. Don't see coleus at all, Mentha.

I can check out Mr. Sub's list, and can also check at my nursery to see what's available. I could probably go with the schefflera.

I'll tell my co-worker that you are all very FRIENDLY strangers! ...and helpful too!

Here is a link that might be useful: toxic plants

Hmm I don't see Sansieveria on the list. I know for a fact it should be, I lost a rabbit to munching on one. they have natural sapoines in them, which cause the liquids in the stomach to bubble, thus suffocating the eater. As a matter of fact this list implies all plants to be safe for animals.
Coleus shouldn't be on the list, as they are in the mint family. Most mints are not considered toxic.

Being taught from an herbalist, I must say this list is speculative.

Mentha, do you know a better resource, online?

Unfortunately this one seems to be the best one, but not all plants are and should be on this list. I did find sans on this list under 'snake plant', but it says it's mildly toxic. I'd say this list has not been completed, because there is no listing of toxicity to animals on any of these.

some examples of misconceptions are: 1. pokeweed young leaves are eaten like any other greens, however the older ones cause problems. 2. Stnging nettle and poison oak are both steeped as a preventative/treatment for themselves. 3. Yarrow is an excellent medicinal herb. 4. taro is cooked and eaten.

I'd add creeping charlie to the list (swedish ivy) mine gets a 1/4 of a turn daily to keep it even, it sits in front of an east facing window with about 4-5 hours of sun light everyday (direct sunlight). I'd also say any plant in time will tend to leand towards the light. Thats one important element in a plants life.

Less impressive as plants, but rather dramatic in demonstrating phototropism, are seedlings. I've used a certain brand of seed-covered terra cotta animal (wink wink) and had to turn it multiple times in one day to keep its "coat" even. It would be a pretty short demo, though.

Depending on how much time you have, starting an Avocado plant (maybe a few) from seed can be a lot of fun...and yes, they do lean towards the light. The kids can witness the seed break open as the roots emerge and watch the plant grow day by day.

Not sure, but Avocado may possibly be toxic...

Well thanks to all you "strangers," for the help. I'll be making a trip to the nursery to see what's available so I can experiment with it a bit this summer.

Naturelover, one of our activities is to start an avocado, so that's on the agenda too. Thanks for mentioning it.

I would think, as lalibellule mentions above, that the most impressive for demonstration purposes would be seedlings. I've forgotten but don't even tiny sunflowers plants turn toward the sun?

Several vegetables will I'm sure.

I don't know if there's any complete list of toxic plants online..(S)
I remember www.birdtalk.com posted a list of toxic plants, but again, don't know how complete it is.
Mentha, I didn't know some Coleus were edible..wow..if anyone goes to the Foliage Forum, check a thread on Coleus, click on the link..They mention coleus leaves as a hallucinigetic high. My 'ex' used to boil coleus seeds and drink the tea to get high..Notice I said, ex..

Some sites mention Hedera helix, (ivy) as toxic while others don't..I keep ivy away from birds to be on the safe side..then again, my friend had a cockatiel who ate an entire Algerian Ivy, (hyprid of HH) and nothing happened..I guess it depends on the child/pet.

Albert, veggies are a great idea. And if eaten, there won't be any problems..Sunflowers too..didn't think about annuals/veggies.

Socks, type in Toxic plants in your search engine..visit different sites. This way, you might get a list w/more detail..Toni