Perennials or weeds

In my garden different plants occur to different times of the season. Some are coming up as tubers through the late spring snow like rhubarb and others are showing their flowers too late for the insects to get help in their reproduction process.

Still they are returning every year. We call them Weeds or are these plants Perennials.

The difference may be in the spreading. Weeds seam to move around in the garden making problems for all the other plants, while Perennials stay more or less at the same place every year.
During the blossom time most of these plants are beautiful like this one. For me no name, but an object worth a post in the Today´s Flower meme.