Any plant with a high DMT content will fall into the same legal grey-area as MHRB: technically illegal but still easily obtainable. IME, the leaves of
Psychotria viridis are not any easier to acquire than MHRB or ACRB. But
P. viridis is however fairly easy to cultivate, and it probably grows faster than
Acacia and
Mimosa species.
P. viridis absolutely has a high enough alkaloid content to be used for extractions, provided one has enough leaf material to start with. There are some great threads on the forum which contain basic outlines for extracting DMT from leaf sources. Here are two of my favorites:
Jamie's Iso Tek and
AlbertKLoyd's Phalaris Tek. Both use similar methods and both should work for most leaf sources with a high DMT content.