What are five examples of different characteristics a plant could possess to allow it be naturally selected?This can be found in Chapter 7.

I think that you really are asking not about natural
selection but about people selecting the plants based on those characteristics.  This
answer lists five characteristics that caused people to be more likely to pick a given
plant.  When they picked it, they helped it become more
widespread.

The five characteristics
are:

1. The size of the
   fruit.


2. Whether the seed of the plant is
   bitter.


3. Whether the fruit is fleshy -- whether it has a
   lot of edible parts.


4. Whether the seeds are oily -- this
   is a good thing because oil has lots of calories.


5. Whether
   the fibers of the plant are long -- this is good for making into
   fabrics.