I would hold on seamaiden. My professor has just returned my inquiry to him in regards to whther a common grass in a container would be considered a dynamic accumulator or living mulch and he replied:
"it probably won't surprise you that i'd like to answer your question with another question, chief: what plant isn't a 'dynamic accumulator'? i imagine some are better than others at the task but, don't they all meet such criteria? i.e., i think you're onto something. thanks for sharing in the fun."
I've answered his question now I'll wait for his answer specific to container growing. I've sent pictures etc. stay tuned..
i suppose all plants could be considered dynamic accumulators, since they all need more than a single environmental input in order to survive. so they accumulate dynamically.
however, that is not a very helpful classification for the gardener, if every plant could fit in to the category.
when i used the phrase i was referring to the MOST capable accumulators---i.e. the plants that collect and store the highest levels of a variety of nutrients, vitamins, minerals, etc. which are often the plants with strong, deep tap roots.
here's another helpful resource:
Dr. Duke's
Phytochemical and Ethnobotanical Databases
my favorite dynamic accumulators are stinging nettle (Urtica dioica), comfrey (Symphytum officinale), and dandelion (Taraxacum officinale). look them up in Dr. Duke's database and see for yourself their value.