Thanks, M and Q.

I'm still trying to find a substitute word for "wallflowers" because I really don't think to the average non-flower-gardener (at least in the US) that word evokes an image of any particular kind of blossom or flower.    Many varieties of wallflower do grow wild, so "wildflowers" might be a better word - a general category instead of the specific.
The botanical name "erysimum" could also be used, if it's important to be literal.

My preference is to render "Manojito de rosas y de alelies" as "Little bunch of roses and wildflowers."