Leonda!
#1 is a Hoya, we have a thread going on in our Houseplants forum
The thread "who loves hoyas?" in
Hoyas forum
#3 (and I think #4) too are Dieffenbachia
The last one has been answered in this thread;
http://garden.org/thread/view_...
Sure others will chime in to help with the others.
It is better to start a new thread for each plant, so not to cause confusion..
