What kind of houseplant do I have?

Question

I just bought a large (~4ft.) houseplant that did not come with a tag. It has large, 12in. long leaves that are dark green in the center and light green along the edges. The undersides of the leaves are dark purple. The most interesting feature of the plant is that the leaves move each night from a "floppy" state (floppy like a banana plant) each to straight up. You can actually see and hear the leaves moving from around 6:30pm-10pm. They curl back down every morning. The leave and stem structure looks almost like a huge peace lily plant, but I can't find anything with the purple undersides in that family...

It is not a prayer plant, the leaves are more long than wide. Also, the dark part covers the entire center of the leaf. The stems are fairly narrow for such large leaves.

Answer 1

Sounds like one of those "man eating" plants!
Please be careful...I've never heard of "hearing" the leaves move.

Answer 2

Most houseplants are hybrids of plant species which grow wild, somewhere in the world. A good rule of thumb for keeping them healthy is to try to match the same environment from which they originated. You may not be able to match every criteria for your plant, but every small step you take to ensure the plants comfort will be a giant step towards keeping your friend healthy.
Proper lighting and watering are, by far, the most important criteria for the health of your house plant, but temperatures and humidity will drastically affect your plants as well. Generally, tropical plants enjoy a relative humidity of 50%-70% and warm temperatures. Unfortunately, when temperatures in the home rise above 67 degrees F., the humidity drops drastically, so it may be necessary to sacrifice a few degrees of warmth in lieu of an increase in the humidity.
Of course, there are always exceptions to the rule. Succulents being the most notable, which prefer warmer and drier conditions. At temperatures below 60 degrees, African violets will stop blooming, Poinsettias may drop their leaves, and the leaves of Gardenias may turn yellow. It will be a great benefit to your plant if you do a little research about what the needs of your particular species happen to be.

Answer 3

You could also go to your local library (go books!) and check out a plant handbook to see what matches descriptions with your plant, and then do a google image search with the scientific name to see what color photos match up closest to your plant.

Answer 4

I believe what you have is a Prayer Plant (Maranta leuconeura). Here's a link with a picture so you can confirm: http://www.thegardenhelper.com/Maranta.htm

Answer 5

It may be Calathea lancifolia, like this picture:
http://hortiplex.gardenweb.com/plants/p1/gw1043083.html