Nope. DNA is not really useful for show boundaries between species, because we all share a lot of it and an only a very specialist expert would know what genes make the flower. Is also very expensive and time consuming.
Plant families have consistent, easily recognizable and often stable floral formulas [1], that don't change among entire tribes. Finding an interval of families to classify our sample is much easier this way, does not need expensive machines and can be done in the middle of a jungle at 1000 Km of the next laboratory. In any case floral formulas are just a small part in the whole picture.
[1] This was the master plan; and now here come the tropics with its own agenda.
