The photo below is of the flowers that the wisteria has. They flower in the start of spring and when the vine is large, the petals create a blanket of purple on the round beneath when they start to die. Bees are highly attracted to this flower probably because of the great odor it releases and I have stepped on few bees while walking under a wisteria when the flowers start to fall of and the bees are still looking for nectar and pollen inside.
The photo shows a small wisteria shaped into a bush, with the right trimming, it will stay that way. When left to grow naturally, it branches out really far and wide and is capable of covering entire walls and trees. Trees can become strangled by the vine as the tree gets bigger and the vine wraps around the trunk.
Below is a photo of what the stem looks like. as the vine gets older the stem gets thicker. We had a really old vine in our garden which had a stem thick enough to hang on and it wouldn't break.
The leaves on in the picture below are fairly new leaves, they still are light green. Once they are mature, the leaves are a darker green and in Autumn the leaves turn gold and fall to the ground, coating the ground in gold.